There's maybe 2 or 3 possible origins for pre-1893. One being from the Imperial Armouries as it is seen on bolt guns & the other is that early on it is seen on Sauer's wares. So it would be interesting if there is an Imperial Eagle on the flats of a Charles Daly completed with a British parts kit. It may have been some sort of material test at Sauer prior to the 1893 rules.

Kind Regards,

Raimey
rse