Looks like a replica Colt Dragoon or a Leech and Rigdon (depends on the caliber) made in Italy and imported by Navy Arms.
These have been being made for years and are still imported by various companies under various names, with Navy Arms being one of the earliest. I think they started importing replicas back in the '60's or earlier. The guns are black powder only and are a lot of fun to shoot and a pain in the patoot to clean. (Hot soapy water seems to work best.) As for value.. I see them at gun shows for $100 to $150. Navy Arms is one of the better ones.
Dean
