Don’y you just hate an empty hole? Seems like there ought to be something filling it!
On the Uberti 1866 and 1873 lever action rifles, most cowboys remove the lever lock that was designed to hold the lever closed when in a saddle scabbard on a horse. Since it isn’t needed by modern cowboys, it is usually removed, leaving a big old ugly hole.
The lock is fashioned from a brass cartridge case head that a brass bolt has been soldered to. A small brass nut secures it to the lower tank of the rifle
The 45 Colt, 38-40 and 44-40 are larger in diameter than the 38/357 case head. They will not fit into the recess that was occupied by the lever lock. They stand a bit proud. They will appear like this: