i have made about 60? of this style of lock and they were all "3 and 4 pin"target rifle locks.In 1980 the captain of the German Internatonal *muzzle loading team had a fine Brazier lock on his Whitworth fail when the main shaft holding the hammer broke and he asked me if I could make a new one, That was my first experience with lock repair and I was able to copy that tumbler to the
exact configuration and used the original "fly".Another 7 years went by and then I copied a complete lock of this type loaned to me by the late Lynton McKenzie and the one recently shown here by BrentD is one of the last ones I made.
Trying to repair a lock with a "major organ"failure with out a lathe and a milling machine to me would be a VERY difficult job and I get tired even thinking of it.
Bob Roller
That German team captain was also a Luftwaffe combat fighter pilot in WW2 and flew the Bf109 and the FW190 in combat and favored the FW190 and said the radial engine it used gave a bit of protection against frontal fire like the tail gunner of a B17 could put out