Ah, with the example being devoid of marks & along with the wedge crosspin, flash protector & large strikers, I'd guess the Roux action variant w/ a horn pistol grip was peddled in the mid to late 1880s. We can be certain the GM initials are not for Gebrüder Merkel as it was formed later. But I'd hedge my bets toward Gustav Meffert or Georg Meffert and I'm sure there are others. Hans Christoph Georg Stein must have been active earlier in the 19th Century and it appears his successor Jobst Berger took the reins circa 1885. So if that holds true, it would date to 1885. I guess the 91 could represent 1891 but if there is another 91 on any other component, it would be a serial nummer or assembly number.
Cheers,
Raimey
rse
