This original, Very Fine condition, Complete Lock and Hammer will fit and function perfect on any Springfield 45-70 Trapdoor. The eagle and Springfield are stamped deep and clear. The firing pin striking surface of the hammer is in fine condition.  The notches on the tumbler and the tip of the sear are in very fine condition. A complete early Model 1877 lock in this condition is difficult to find. This Lock will fit & function in all Models including 1873, 1877, 1878, 1879, 1884, 1888 Springfield Carbines, Rifles and Cadets.