1915 WWII bringback
 

Here is another portrait type photo of a Luger I bought many years ago from the vets family. When I got the rig home I looked in the bottom of the holster and the capture papers were balled up there! I used a steam iron to very carefully "unball" the papers then I pressed them under a stack of books.

The pistol was used in the Great War then pressed into service again in WWII. I don't think the holster is WWI, it is completely unmarked?

Seeing the construction of the back of the holster will help narrow down a time period for when it was made.