Your second Luger is rebuilt with parts from a number of different Lugers and arsenal rebuild replacement parts.
The "byf" prefix didn't start being used until 1941 (the Mauser concealment code was "42" until 1941 - so all 1940 made Mauser Lugers will have "42" on the toggle).
The side plate is an arsenal replacement part shipped from Mauser as a spare part.
The "byf" toggle is marked in a non-standard way. It's original serial number marking at the rear was removed.
I don't recognize the form of the eagle stamps on the barrel. I'm not sure that the replacement barrel was done by an arsenal or field replacement workshop.
__________________
 Igitur si vis pacem, para bellum -
- Therefore if you want peace, prepare for war.
|