Badger, perhaps worthy of mention - 1920 is not actually a date "per se". "1920" is the ownership stamp of the Weimar Republic. It was added to all former Imperial arms set aside under the strict limitations of the Versailles Treaty for use by the severely limited post-war German Armed Forces.
1920 refers to the year the weapons program came into effect after the bickering and in-fighting amongst the allies in 1919 to determine how severely to hamstring the new German gov't. Of course, we all know they went to far and basically set europe up for the next war 20-odd years later. hindsight is, after all, 20/20.
A rifle, Luger, etc. marked 1920 was not generally inspected 1920. It could have undergone arsenal service, inspection or repair anywhere from 1920 to about 1932 or so, but generally most would have been so marked 1920-1925 when the program was ramped up.
All the 1920 refers to is that the weapon was inventoried by the allied Versailles Inspectors and allowed into German Army stores as part of their treaty limits on small arms. Most such arms, of course, eventually came to serve Nazi Germany, many coming to Canada as vet returns in 1945-46.
