What is the value of a 12 gauge Nitro Hunter double barrel stainless shotgun with hammers serial 5915?

'Nitro-Hunter' was a known trade name used by the Belknap Hardware Co on shotguns they retailed through their mail-order catalog before World War I. Since your gun has hammers, I suspect the origin is Belgian. Remove the barrel set and look on the underside for the telltale Belgian proofmark of the letters ELG in an oval. There is a possibility the gun was made domestically, probably by the Crescent Arms Co, in which case it will not have the Belgian proofmarks. It certainly is not stainless steel. That material was not used in firearms until many decades later. Perhaps someone has had it ... plated....... Value is as a decorator only. Typical specimens sell in the $100-$200 range with most under $175. If it has been nickel plated, who knows. sales@countrygunsmith.net