Desertmoons,
Frank Fish found a strongbox from a stagecoach robbery at Robber's Roost near Mojave, Ca in the 1950s. There is a picture of him holding some of the wea[pons recovered from the cache in his 1961 book "Buried Treasure and Lost Mines". The description says (2) Colts Cap and ball revolvers.If your pistol came from anywhere near Amador, Ca. It may have been in his Treasure Hunting Museum there. You could also try and contact Lake Eerie Schaeffer's Family (close friend of Fish) to see if they have heard of it.
Mike