Steve,

#1. This rifle seems to be in good shape. I would assume the sight has been lost as the rifles did have sights.

#2.The crown on the lockplate indicates it was manufactured to Crown(meaning for military service) specifications.

#3. The marks on top of the barrell are proof marks. By this I mean it has been "proofed" or tested for quality.

#4. The markings on the butt plate are individual unit rack numbers. These weapons were not manufactured with serial numbers. Once issued they were given a number to record which unit to which it was issued, and a rack number indicating its place in the armory. As the U.S. military of that time did not do this on a normal basis, I believe what you have is a specimen of Enfield rifled musket which has been issued to a British Army unit at one time or another.

My observations may not be the most accurate. I would welcome any comments on what I have stated here.

Len