Well, a couple of points. The Germans did not run the same numbers over and over to disguise production figures. Their numbering system involved a letter suffix. Numbers went from 1-9999, then 1a-9999a, 1b-9999b, and so on. Plus each maker used the same system and they started each year at 1. So a complete Luger description has to be the maker, the date, and the serial number with suffix. Example: Luger pistol, made by Mauser (code byf) in 1942, serial number 1234b.
The straw color is the result of the heat treatment of the part. With time and wear, it may lose the yellow color and become white; it does not turn plum color. Plum color on those parts is the result of hot tank bluing on certain alloys or heat treated parts. In 1937, Mauser stopped using rust bluing and straw coloring parts and began tank bluing of everything. After that, the parts formerly straw color became blue or plum color. Parts were tank blued by American gunsmiths also, when refinishing the guns.
"Most" Lugers in the country today shoot 9mm, as they are wartime bringbacks and that was the German military/police caliber; the 7.65 (.30 Luger) was not in the supply system in Germany. Most .30 Lugers are guns sold in the U.S. after WWI, when German makers were banned from producing guns in the military 9mm caliber, so they reworked ex-military Lugers to 7.65mm for sale to obtain desperately needed hard currency.
As to that odd takedown lever, it may very well be a gunsmith-made replacement for a broken lever, maybe by someone who did not have an original to copy. If so, it is not a bad job, but it doesn't look like factory work.
Jim
