If it was in new condition, it could be worth $200+, but since it's already worn, it may be worth only half as much (or possibly even less). As a collectable, re-finished/restored is equal to worn-out (no ORIGINAL finish remaining), so you won't be doing any monetary damage to it. I'd suggest just cleaning the wood with a good furniture cleaner and the metal with gun oil $ brass wool. Whatever you do, don't attempt to have it hot-blued or you may find yourself with two single barrels. (You probably can't do that yourself anyway and a competent gunsmith should know better.)
50-500 usd
20-100 usd
The St. Louis Arms Company was a trade name used by the H&D Folsom company of New York on low cost shotguns they sold to the Shapleigh Hardware Company of St. Louis in the late 19th and early 20th century, up until about the Second World War. The value is not high.
Need more detail. Generally $400 to $800 range
St. Louis Arms was a trade name sold by Shapleigh Hardware of St Louis and also by Sears Roebuck. They were mcde by Henri Pieper in Belgium c. 1890-1914 They were later made in the US by Crescent Fire Arms Co and J. Stevens Arms Co.
"What is the value of a Diamond Arms 12 Guage single shot dated 1893 made in St Louis Mo?"
One of many companies that made inexpensive firearms at the turn of the century.
Central Arms Company was a trade name used by the W.H. Davenport Firearms Company on shotguns made for the Shapleigh Hardware Company of St. Louis. MO.
Hartford Arms Company: Trade name used by the H. & D. Folsom Arms on shotguns made for the Simmons Hardware Company of St. Louis, Missouri. Unlikely that it was ever on a stagecoach. Laminiated steel barrels were not designed for modern ammunition, so even if it does work, don't use it.
I believe that King Nitro was a model name of Shapleigh Arms Co, St. Louis, MO.
If this is an A5 shotgun, it is on the left side of the receiver. The sn starts with a letter A, B or C
Berkshire shotguns were manufactured by Meriden Firearms Co, Andrew Fyrberg Mfg Co, and Crescent Fire Arms for Shapleigh Hardware Co of St Louis and Sears Roebuck.