Lots of info available. Wm Moore was a London gun-maker pre 1870's when he went in partnership with Grey. Many Moore shotguns are Belgium knockoffs. Belgium barrel proof marks will have a crown and elg or some form of elg. There is a website that shows proof-marks of the different countries. The Englishproof-mark will probably be a crown with crossed sceptres below and the Letters BPC arranged within the angles of the crossed sceptres. Proofing with this mark was done in Birmingham, circa 1867 to 1928. Barrels were not necessarily proofed in London, but this does indicate English manufacture. Generally, Wm Moore shotguns (really of London) seem to date from around 1860's. Before that time he worked for someone else.
0.5625 G mm'
You only have twenty five seconds for one shot, or twenty five seconds to live. I'm not sure, could be either.
describe the type of shotgun and recheck the serial number
I believe 938 is a German silver marking~
585 Marking on Italian jewellery indicates it is 14K gold
Model designation
Noidea I've same marking too 18k tbe
This shotgun is in the neighborhood of 100 years old. There is fairly extensive information online available on this shotgun.
$250-$350
Hopkins & Allen
Try the Gun Parts Corporation online
If it is a double, remove barrel and you will see it along with serial #.