1920 non-comercial?

[mrerick]

You may have a Weimar property marked Luger. That or a 1920 manufactured DWM Luger receiver. The 1920 is in the more rearward position of a Weimar manufactured DWM luger.

It is not usual to see the front of frame serial numbers offset to the side. They were centered. The typeface of the dies is not standard to DWM either.

This may have been scrubbed and renumbered.

DWM was no longer in business when the Nazis came to power.

I can't see the top of the receiver well enough in your photo to see if it was manipulated.

My initial impression is that someone assembled this from parts of different guns, and renumbered the frame to look like it matched the upper receiver.

Get good sharp well lit (natural light - not flash) photos of the other markings on the barrel, receiver and proof symbols and it will be possible to tell more.