Well, first of all, it looks brand new, not fitting an item that should have been well used about 76 years ago. Also, the stampings on the back look like they were obviously put there to make the holster seem to be "a rare SS-marked holster." To the best of my knowledge, German holster makers didn't go to any lengths to mark holsters according to special units. The "death's head" stamping is way overkill. The format of this holster screams "cheaply machine-made." For example, the real holsters had molded leather clam-shell tops that protected the gun from dust, rain, mud, etc. This holster exposes its contents. The body of the holster is folded over to form the top half instead of using a separately-crafted piece.
For comparison, here is a genuine German P.38 holster from 1943.
I think you have a modern-day fake designed to appeal to the unwary. Just my opinion.
John