Hi Norme,
I went back to the pistol and looked more carefully armed with a really high powered loop. Well, I am relieved to find there is both a serial number and an acceptance stamp on the pin; but, it is a very light strike. The light has to hit the metal at an angle and then the serial number and stamp reveal themselves and the SN is marked to the pistol.
The retainer is also stamped. In my concern over the firing pin, I did not look at it carefully. The mark on the retainer is a better strike but it too is shallow.
I am surprised that such a stamp crazed arsenal like Erfurt would have allowed light strikes to pass; but, I guess it was good enough for government work (no offense to any federal employees who might be reading this...just a joke

).
Richard