OWD,
Being in the office at the moment I don’t have access to any reference books but I think you’ll find that after a certain date (1884 perhaps?) guns of foreign manufacture (foreign from a British point of view) were proofed with a different set of marks which denoted the fact they were not of British make. The marks in the photos are just the normal ‘home’ proof marks.
That aside: Regarding the ‘star’ trade mark (or whatever it is) – they look to have been quite a roughly done – not at all like the rest of the gun. I wonder it they were added by someone other than the maker?
A long shot would be to look through the published list of makers serial numbers (in Browns books for example) - it would at least eliminate many makers as their number ranges would be way off for the likely period when the gun was made.
Regards
Russell
