American Arms was a trade name used by the H&D Folsom Company of New York on firearms they retailed circa 1900. It could have been manufactured by any of a dozen makers, but most likely by Crescent Firearms. Like any other 100-year-old tool or machine, parts are where you find them. You may be able to get parts that fit (or can be made to fit) from a local gunsmith or at a gunshow, but no one will have a catalog of parts for it.
try numrich gun parts
Try gun shows, Shotgun News, Gun List, local gun shops.
numrich gunparts.com has everything but the stock
Your gun is a Mossberg 500 with a Wards name. If you can't get parts from a local gunsmith, try Numrich Gunparts
Try e-gunparts.com, gun shows, gun shops, Shotgun News.
Pretty much an impossible undertaking.
Try Numrich gun parts corp.or gun broker.com under shotgun parts.
Try e-gunparts.com, Shotgun News, Gun List, local gun shop, gun shows.
On line gun auctions, gun store, gun show, want ads.
I would start my search at Numrich gun parts corp.They may be found on the web.
try gun parts at: 501 767 1470
it's an 1850 american gun co. double barrel shotgun made in baltimore maryland