Is there a date stamped on the barrel tang that matches the lock? Should also be other markings in the breech of the barrel like a VP and an eagle. Maybe others being a Harper's Ferry gun. Also on the stock, opposite the lock there would have been some stock cartouches, script letters in ovals or squares stamped into the wood.
I ask because these things can make it more valuable. Also could prove that parts were changed in it sometime during its life. The M1842 musket had interchangeable parts, so if something was damaged, or missing it could be replaced. These things can determine the price someone is willing to pay.
So far all I can see is the missing hammer screw. Looks like the head snapped off and the screws broke off in the tumbler. Can be a tricky fix. Maybe some sort of repair behind the lock?
I don't think the sling is correct for the musket, looks later to me.
