[mrerick]

The acceptance stamps were associated with a lead government inspector by number. During 1940, at Mauser Oberndorf the inspector was number 655. That inspector left Mauser in 1941 and was replaced by inspector 135. Later in 1943, the Eagle over number dies were changed to Eagle over WaA135 dies.

The codes are listed here:

http://en.wikipedia.org/wiki/Waffenamt_codes

Parts were inspected and accepted in batches. It's certainly possible for parts from an earlier inspection batch to be used in a later manufactured pistol.