This is a civilian contract rifle - the ones delivered to BOTH sides during the Civil War. These are Birmingham proofs. They are detailed, but too small to see that detail!
The three marks are (from left)
View attachment 512059 provisional (first) proof (before rifling often straight from the forge);
25(-bore) provisional bore
View attachment 512062 final view (intermediate proof) ;
25(-bore) final view bore
View attachment 512061definitive (final) proof
Some rifles may be seen with
25 24 meaning a barrel that was first bored at .577" but was finished as .58" for Union forces.
The
view may be made before rifling or with just rough rifling.
London proofs are different!
BTW - The screw on the hammer is not the original either