Help with mark ID
 

Does the enclosed mark look familiar to anyone out there in global cyberville ?? It resembles a current Swiss military
mark, but has one less "bump"(upper left). Someone suggested
it is a pre-war,wartime Swiss mark.....which was changed to the current 3-bump Swiss mark after the war....?
Thanx in advance for any help.
Charlie, chazcrist@gmail.com

As stated in John Walter's book "The Luger Book" (and other sources), page 82, this is the so-called "Bernerprobe" proof, seen on Swiss military lugers 06 W+F and 06/29, applied by the government factory at Bern, Switzerland. It usually lies on the front left side of the receiver ahead of the trigger plate.

Here's a fair example: