[Johnny Peppers]

The number inside the sideplate was the same as the first two digits of the serial number into late 1938 or early 1939 Mauser production, when it was changed to one digit higher.

DWM used the same number as the first digit or a three digit serial number or the first two of a four digit serial number inside their sideplate which was stamped on the lower shelf of the sideplate, but to the best of my knowledge Erfurt did not use it.

Does anyone have a two digit serial number that they will check?

The sideplate probably required more hand fitting than any other part on the Luger and possibly this prevented the sideplate from being mixed with the sideplate of another Luger only a hundred digits lower or higher.