Hi,
A nice gun, with a nice original Mauser presentation case (most came in rather bland foam boxes with cardboard lids).
The gun is an early example (1970-1972) of the post-war Mauser Parabellum, made by Mauser in Oberndorf. The guns were made using the Swiss design as a guideline, therefore they have the look and feel of the Swiss-made Parabellums, although not a snippet of Swiss tooling was used by Mauser.
The gun's serial number is also visible on the target, so no need to conceal it

The 10.00... visible on the frame is only a prefix that says it's 9mm (10).
Needless to say this ain't a $400 piece of kit...