Need some ID help. A friend of mine has a percussion pistol that appears to be altered from a musket. Looks like an 1816. The lockplate is dated 1857 US Remington Ill. and has the Maynard primer. The barrel is dated 1856 and the top of the breech stamped City of Philada in a half circle over A. Werfflien. Smoothbore with a 15" barrel. He believes it may have something to do with the Philadelphia mint. Any ideas would be appreciated.
Thanks, tom