Kevin, From the description given, PLEASE do not think of firing that old double gun just yet. Being a family piece it would be a shame to blow it up, and how would your ancestors feel if they knew that you lost an eye, fingers, hand, or life because of it. It sounds as though all of the opinions of the judges of the condition of this firearm are based on your description. In my opinion there are several red flags, I 'll list a few of them: Most of the old double guns with an exposed hammers were damascus barrels; Apparently it is rusted heavily because the manufacturor's name or model isn't legible and the action is frozen with rust, so there will be a lot of rust within the laminations if it is a damascus gun; Even if it isn't a damascus barreled gun the condition as described would definitely warrant a personal inspection by a professional gunsmith; These old shotguns were all very similar in appearence, so it may not be the model you suspect; The box of ammo you found doesn't really support the present condition of the shotgun it was most likely used in the gun before storing in an outbuilding. My intention here is not to damn anybody's judgement or ideas, or your shotgun. I would hate to see you or anyone harmed or your family keepsake. PLEASE GET IT INSPECTED BY A PROFFESSIONAL GUNSMITH!