Armi San Marco was one of the first Italian manufacturers to make replica Colt black powder revolvers. Quality varied quite a bit, but typically wasn't as good as other replicas of the day. Some variations had parts that were not heat treated properly. Depending on the model/variation, most black powder derringers/revolvers are currently valued in the $50-$395 range.
Previous manufacturer located in Gardone, Italy circa early 1960s-2003.