Try www.gunbroker.com and www.auctionarms.com for a good look at what various guns are selling for. Singleshot shotguns can be quite economical, but some are rare and are much more expensive.
Impossible to answer without a sn. Even then....
Numerous companies in many countries have made single shot 12 gauge shotguns.
1958 - 1970 I was told
Its a Sears branded Mossberg 500.
ARMORY GUN CO was a trade name used by H&D Folsom Co on shotguns made by Crescent Firearms and distributed to the hardware/catalog trade. Would have been made between 1890-1910, give or take.
Manufactured between 1886 and 1916. Retail value $50-$75 unless in like-new condition.
very good question. new york arms co. is nowhere to be found. have very old 12 gauge single barrel shotgun stamped "GENUINE ARMORY STEEL" and "CHOKE BORED" "NEW YORK ARMS CO." New York Arms Co was a trade name manufactured by Crescent Firearms. Genuine Armory Steel - Choke Bored is also a Crescent marking. They also used the name Armory Gun Co.
Sears Slug Model 446.511761 is a Mossberg 500. All parts interchange.
Shotguns That Kick was created on 1914-12-03.
Manufactured by Crescent Fire Arms Co sometime between 1893 and 1932 and worth $150-$250, depending on condition.
Modern Marvels - 1994 Shotguns 12-66 was released on: USA: 2006