A date is only as useful as the evidence behind it. Each instrument record should tell you where the answer came from.
Serial tables and production information published by a manufacturer.
Dated catalogues and documents that add context to a production period.
Published reference works, with their author and methodology identified.
· docs.google.com ·
· web.archive.org ·
· www.hohner.de ·
· concertina.org ·
· concertina.org ·
· concertina.org ·
The record shows a range rather than a point date, and the archive keeps the competing references instead of silently picking one.
No. Model and factory information may require evidence beyond the serial number. Unconfirmed details remain clearly marked.