First Post - Need Help with Navy Marked Luger

[JTD]

Heinz I do not see how a 4" 9mm barrel draws a question?
It was probably an Imperial military that got scrubbed of war time proofs, reworked, rebarreled, and diverted to the Baltic Weimar Navy. Lack of barrel guage and proofing is the inigma.

[Heinz]

Most reworks for Weimar police or military use the original barrels with the addition of Weimar property markings to distinguish them from new production. In the odd case of a new barrel, they have the original receiver, proofs and date marking. Many have the 1920 stamp. New production was regulated by the treaty of Versailles which mandated the short barrels and less than 9 mm. requirements.
Outside of the above two streams of Lugers, military reworks and civilian new production, we start to see a whole bunch of irregular Heimgemach (homemade) stuff. The barrel on this example seems to have been hand-stamped with a slightly out of size font. The receiver is unnumbered and unproofed but appears to have parts original to the frame.
I do not think any of the examples like this came out of government reworks, certainly not DWM, or Simpson, or Mauser. To me "Weimar rework" implies government sanctioned work.
Pieces like this example are just as likely to have been reworked in the US, where a number of rework mills existed, and are outside of the realm of mainstream Luger production history. With all the piles of Lugers in inventory, why would the Navy want this gun?
It looks like a nice shooter that needs to be checked out for safety.