Was able to get my hands on a 1862 Tower Enfield. Discussion with some knowledgeable people indicates that the weapon is most likely period, not a reproduction. It is a second-tier rifle, probably made for national militia or perhaps Indian troops. It has been converted to a shotgun, as the barrel has no rifling. How common would that have been? We suspect that the change over was after the CW when rifles were being manufactured using cartridges.
Thanks for any direction that might be provided.