Rebuild Plates, Secondary Opus Numbers, and Layered Instrument Identities

Builder identity, rebuild history, component provenance, relocation, and present condition are five separate questions, and a mark on the instrument usually answers only one of them. Builder identity is the firm that originally built the instrument. Rebuild history is the sequence of later firms and later contracts, which includes a successor firm working on a predecessor’s instrument and a rebuilding firm applying its own number to another builder’s organ. Component provenance is where the parts came from: a supply-house console, chest, or pipework inside another builder’s instrument is a documented pattern, and so is earlier pipework carried into a later instrument.

Relocation is whether the instrument has moved, and instruments have been relocated and reassembled by a third firm that built none of the original. Present condition is what the instrument is now, and the documented patterns include earlier chests and regulators retained under later work, a replacement console fitted to earlier chests, a modern control system installed inside a retained console shell, a new instrument that absorbed identified ranks from the earlier organ on the same site, and an instrument assembled from parts of several organs.

Two further traps sit at the edge of builder identity and are worth naming because they imitate it: one firm’s instruments sold under another firm’s nameplate or a distributor’s brand, and new work executed in the original builder’s visual style, which can make later material look original. A corporate name shared by unrelated businesses is a naming problem rather than a layering problem, and numbers that coincide across firms are a separate question again; Why Two Builders Can Share the Same Opus Number owns both.

A number in a builder’s series does not by itself establish new work by that builder, because documented series include rebuilds, and rebuilding firms assign their own numbers to other builders’ organs. The same limit applies to a plate. A rebuild plate records that the named firm worked on the instrument under that number; the original builder’s plate records the original contract; neither speaks to what has happened since it was fixed in place, and neither reports what the other firm did.

The console is the clearest single case, because consoles are replaced and rebuilt by firms other than the original builder, so a plate or date on the console belongs to the console rather than to the organ. Why the Date on a Console May Not Be the Date of the Organ explains what a console can and cannot date. Even an interior number that does not fit the builder’s usual pattern is only a clue: a regional survey reports one Balcom & Vaughan console with a nonconforming interior number and reads it as a possible rebuild indicator on the strength of similar cases, which is a practitioner’s hypothesis drawn from one instrument, not a general identification rule.

Where plates, stamps, and numbers are physically located on an instrument, and how to inspect for them, is a separate subject from what a mark proves once it has been found. So is the weighing of physical, archival, and database evidence against one another, and so is the final decision of how to attribute a composite instrument. This page stops at the reading of the marks and records themselves.

A rebuilder’s opus number is a real opus number in that firm’s series, and it can attach to an instrument the firm did not build. In the documented Schantz cases below, the firm’s series includes both its own instruments and rebuilds of other builders’ work, and a published record can carry the rebuilder’s number as its headline while the original builder’s number sits on a separate line. The number identifies the project, not the maker of the pipes and chests it was applied to.

Schantz Organ Company projects supply the best-documented case. Several Schantz rebuilds of instruments that originated with other builders carry Schantz opus numbers, among them 2151, 2161, 2338, and 2343. The OHS Pipe Organ Database records at least six Schantz opus numbers against instruments originally built by other firms. They include Opus 1565, a console replacement on Skinner Opus 402 at Pottstown that the database dates 1978; Opus 2151, dated 2000, on Skinner Opus 816 at Severance Hall; Opus 2161, dated 2000, on the Hill, Norman & Beard instrument at Melbourne Town Hall; Opus 2197, dated 2001, on Reuter Opus 1368 at Northminster Presbyterian; and Opus 2274, dated 2007, on Skinner Opus 634 at Rockefeller Chapel.

Those examples support caution rather than a rule. They show that a Schantz opus number may identify a Schantz project rather than the original builder; they do not establish a universal numbering policy, and Schantz nameplate practice on rebuilt instruments is not established by the published sources, so the number rather than the plate is the evidence to work from. Six is a floor rather than a full count, because the database’s opus field is numeric-only and its search filters do not cleanly separate rebuild records from original ones.

A letter suffix such as -A, -B, or -C marks subsequent work at the same location while keeping the base number of the earlier instrument, so a suffixed opus number is still an opus number, and its base number still points to the original contract. The archived Aeolian-Skinner opus list explains the suffix in those terms, and a commercial project list shows the consequence in an entry for Aeolian-Skinner Opus 825-A dated 1953: a base opus number from the Skinner Organ Company range carrying later Aeolian-Skinner work. That explanation belongs to the Aeolian-Skinner list, so a suffix on another firm’s number is worth reading against that firm’s own published list rather than assumed to follow the same convention.

Holy Cross Episcopal Church supplies a worked case. The church records its E. M. Skinner Opus 306, a 1920 instrument with an installation date of 1921, as reworked in 1949 by the Aeolian-Skinner Company with some of its tonal resources replaced, and the result was designated Opus 306-A: later work by a different corporate entity attached by suffix to a base number from an earlier one.

The suffix also breaks the assumption that a low number means early work. The Diapason identifies G. Donald Harrison’s final project before his death in 1956 as Opus 205-A at Saint Thomas Church, New York, a mid-1950s Aeolian-Skinner job on a three-digit base number from a much earlier era, so the numeric size of an opus number is not a guide to the date of the work associated with it. Reading a base number against the firm’s published list, and knowing what that list’s year column records, is the subject of How to Read an Organbuilder Opus List.

A prefixed opus number identifies a contract in the prefixing firm’s series, and in the documented cases that contract is work on an existing organ, whether the firm’s own or another builder’s. As of September 1, 2026, the OHS Pipe Organ Database opus field accepts alphabetic prefixes, and a Schantz rebuild of Schantz Opus 346 is numbered Opus A346: the record reads “Schantz Organ Co. (Opus A346, 2023)” over “Originally Schantz Organ Co. (Opus 346, 1958)”.

M. P. Moller, also rendered Möller, used an R prefix. A prefixed Moller number identifies a Moller contract, not necessarily a Moller instrument: Opus R-572 of 1956 is recorded as a rebuild of E. M. Skinner Opus 381 of 1922 with a new console and twenty-three new ranks. Database notes attached to other R-prefixed Moller records describe them individually as rebuilds, renovations, electrifications, releatherings, and alterations of existing organs, including releathering and rebuilding a former theater organ along with a new console, electrifying and rebuilding Moller Op. 1430 by its original builder, and releathering and electrifying 1912 Moller Op. 1448. Those are contributor notes rather than factory documents; they describe individual contracts and do not define the series, and they establish that such contracts exist, not how common they are.

A prefixed number read from a secondary record is worth checking against the factory specification before it goes into a report, because secondary records can disagree with each other on the digits. Two Pipe Organ Database records disagree on the number of the same 1968 Moller rebuild contract at First Presbyterian Church, Washington, Pennsylvania: one entry is headed Opus R-786, 1968, while a 2024 note on the related entry describes the same work as R-768 in 1968. The difference is a digit transposition inside one database, and choosing the more recent line does not resolve it.

A builder can also record later work on its own instrument under the original number with no suffix or prefix at all, so two records with the same builder and the same opus number can describe work decades apart. In the same database and as of the same date, rebuild records can carry the same opus number as the original instrument by the same builder: one reads “Schantz Organ Co. (Opus 2209, 2023)” over “Originally Schantz Organ Co. (Opus 2209, 2003)”, and another reads “Schantz Organ Co. (Opus 1889, 2023)” over “Originally Schantz Organ Co. (Opus 1889, 1989)”. In that form the year, not the number, separates the rebuild from the original contract, and the “Originally” line is the signal that a later project exists.

A well-structured record puts the rebuilder’s number on one line and the original builder’s number on another, and the two numbers belong to different firms and different numbering systems. As of September 1, 2026, the Pipe Organ Database renders a rebuilder’s own opus number as the record’s headline opus while the original builder’s separate opus appears on a subordinate “Originally” line: an opus search on Peragallo Opus 772 returns “Peragallo Pipe Organ Co. ( Opus 772, 2022)” above “Originally Reuter Organ Co. (Opus 1368, 1962)” at St. Malachy Catholic Church, Brownsburg, Indiana, 98 ranks. Read the headline as the latest numbered project and the “Originally” line as the builder identity.

Institutional documents make the same separation in prose. A stoplist document hosted by the OHS Pipe Organ Database for Westminster Presbyterian Church, Portland, Oregon, records one instrument carrying two builders’ opus numbers: M. P. Moller Opus 6974, dated 1941 in the document, rebuilt in 1957 by Balcom & Vaughan as their Opus 635, the 1957 work replacing the console and adding twelve ranks to the original nine while retaining all the original ranks. At Salem Covenant Church, Worcester, Massachusetts, the instrument installed in 1969 as Reuter Opus 1684, with two manuals and 26 ranks, was enlarged by Reuter in 1980 and had its console rebuilt in 2022 by the Faucher Organ Co. of Biddeford, Maine, as that company’s Opus 59, so the two numbers attach to different parts of the same instrument. In each case the later number tells you which firm did which work and when, the earlier number tells you who built the organ, and neither replaces the other.

When two headings disagree, work out which firm each number belongs to before deciding that either heading is wrong, because a heading can place a number next to the wrong name without being false. A broadcast profile for St. Andrew Lutheran, Mahtomedi, Minnesota, is headed “1927 Casavant; 2001 Schantz organ, Opus 1177, at St. Andrew Lutheran, Mahtomedi, Minnesota”, while a separate listing for the same instrument identifies it as Casavant Opus 1177 of 1927 with a Schantz renovation in 2001. The opus number in that heading belongs to Casavant, the original builder, not to Schantz, the firm named immediately before it.

The habit that resolves this kind of heading is to pair each number with a firm and each firm with a dated event, whether original contract, rebuild, renovation, or console replacement. A heading that compresses three of those onto one line is still usable once each element has been returned to its own layer, and a database record that prints them on two lines has already done that work for you.

Pipework, chests, and consoles inside an organ can have been made for a different instrument, and when those parts carry their own numbers, the numbers identify where the parts came from rather than who built the organ they are now in. A 2021 renovation account of an Estey instrument, written by the organbuilder who examined it, states that “Opus numbers, stamped on the pipework, indicate that most of the pipework was originally made for an organ built by Estey (opus 1914) in 1921 for the Pennsylvania Hotel in New York City”. Further pipework in the same instrument is marked as coming from Estey opus 3048 of 1933, so one instrument carries two opus attributions, each read off the pipes. That is a single instrument, with no published photographs of the markings and no independent verification; it documents that stamped opus numbers were found on this pipework, and it does not establish that Estey stamped pipework as a general practice or say where else on an instrument an opus number may be marked.

The Salt Lake City case shows the same layering at the level of whole assemblies. First United Methodist Church states that the historic pipes and chests of its 1906 George Kilgen and Sons organ were retained, combined with a purchased vintage Austin console from Austin Opus 1702 of about 1930, and rebuilt and enlarged by Bigelow & Co. Organ Builders as Bigelow Opus 38 with three manuals, 36 voices, and 43 ranks, with a rededication date of 10 January 2016. Three firms are present at once: Kilgen in the retained pipes and chests, Austin in the console, and Bigelow in the number the instrument now carries. The account is an owner narrative that mentions a 1924 enlargement without detail and does not itemize the boundary between retained Kilgen material and new Bigelow material, and because the console came from a third builder, neither the console nor the nameplate on it can be used to attribute the instrument.

Whether a given rank inside your own instrument came from elsewhere is a question for that instrument’s records and for physical examination, and reading stamps and marks in place belongs with the separate subject of where marks are located and how to inspect for them.

An instrument that has moved, or that has passed through several firms, gains a layer with each event, and a later event can add a number that does not describe the earlier layers. A rebuilding firm publishes a project at St. Paul’s R. C. Church, Princeton, New Jersey, under its own Opus 38, describing an instrument originally built by Ernest M. Skinner as Opus 537 in 1925 for the Peabody Conservatory of Music in Baltimore, and the same firm states that Opus 537 had already been modified in the 1940s and again in the 1950s by Aeolian-Skinner before its later rebuilding. Four layers sit on that one instrument: the Skinner contract, two rounds of Aeolian-Skinner work, the move from Baltimore to Princeton, and the rebuilder’s own number.

The Lehigh Valley chapter of the American Guild of Organists records an instrument at St. John’s Evangelical Lutheran Church that passed through four firms. It began as a 1938 Skinner-family organ, and a 1969 Lehigh Organ Co. renovation made significant and permanent changes to the scheme and sound. A 1992 Reuter rebuild designated Opus 2163 was contracted to “rebuild, redesign, and refurbish the organ, using many of the old ranks of pipes, provide new ranks of pipes to complete the desired scheme”, and Walker Technical Company digital stops added in 1998 brought the instrument to 87 ranks on four manuals. Reuter Opus 2163 is the one opus number named in that account, and it identifies the 1992 contract rather than the 1938 organ or the ranks that survive from it.

Moller’s documented instruments show how varied the later events can be. Four separately documented Moller instruments were altered after their original installation: an 1897 organ was moved in 1933; a 1941 organ received a third-party console rebuild in 1957; a 1969 organ was enlarged in 2004 and moved to a new sanctuary in 2024; and a 1959 organ was renovated in 2024 with a third-party control system. Those cases establish only that an owner should check an individual instrument’s later records; they say nothing about how frequent such alterations are.

Present condition is the layer that describes the instrument as it stands, and it is the one an owner is best placed to document. Earlier chests and regulators retained under later work, a replacement console fitted to earlier chests, and a modern control system installed inside a retained console shell are all documented configurations, and in each of them what is visible from the outside does not date the material still working behind it. For that reason a condition record, a service agreement, or a project scope should describe the number on the plate and the fabric behind the plate as two separate things.