H-block staging entry validated for model fit. Imported from staging batch duell-thimm-h, source entry 962.
The local 1891 year was a polluted carry-over from a later handbook line in the same Thimm cluster. Both Gelli and external secondary evidence support Hamon's London manual in 1827, so the catalogue restores 1827 as the credible date.
Vigeant 1882 preserves the London 1827 Hamon witness and explicitly identifies the author as a master in the art of arms, with lithographed plates.