pls suggestion about my luger 1915 9mm

[A.Mifsin]

Originally Posted by MFC

IIRC all Erfurt receivers have the rear sight notch, both LP08 and P08. The proofs on the right side of the receiver will determine if it is an Erfurt or a DWM receiver.

So, if I have an Erfurt without proof marks and no date but only the serial number on he left side is either forced matched reciever or buffed so much that all marks disapeared.
Where there any commercial Erfurt Lugers?
Alf