[mrerick]

It looks like it was ground of when the gun was refinished and heavily buffed. The serial number on the barrel was also removed.

You can see that the receiver is a little proud of the frame.

Don, the problem that that creates is that the legal serial number of the Luger is the one on the front of the frame, including the suffix letter (which looks like "d" on your pistol).

The assumption would be that the gun's serial is 3773d, but the numbers elsewhere may have been changed.

The obliteration of that serial number, and the addition of the numbers on the receiver and other parts by engraving (and not in the DWM font either) indicates that the gun's serial number may have been manipulated.

That is an ATF issue, and a likely violation of law. I believe that there is a process for adding back the serial number, and making it legal again, but don't know the details.