1) M1816. This lock is a reconversion of an M1816 lock with a poorly fitting brass pan. The “SPRINGFIELD 1818” markings at the back of the lock are incorrect, as an “I” stamp was used in place of the “1” stamp in the date “1818”. There is a small “US” marking at the base beneath the rear of the pan. The inside of the lock has several arsenal stampings, including “AW”, “P”, “M”, and more. CONDITION: lock appears to function well and has a medium gray overall patina. 2) M1816. This lock is a drum conversion of an M1816 lock by M.T. Wickham. The rear of the lock is marked “PHILA 1834”, and the markings in front of the hammer read “US & M.T. WICKHAM” in an arc. CONDITION: the lock does not function and has a dark overall patina. The hammer has a lightly cleaned patina, and the drum is loose with a gray patina. (02-22469/BF). $200-300.