This is an early G.33/40 made in 1940.  Because of the markings on this gun, I believe it to have been issued to the SS.  A lot of collectors will turn up their noses to this statement but read further.

The receiver has only the initial waffenamt from the inspection after the receiver was made.  There are no final waffenamt acceptance stamps.  The same is true of the right side of the stock.  No final acceptance stamps that you would normally see on an original rifle inspected by the Heer inspectors.  Only the initial inspection waffenamts are found on the underside of the stock.  

Lastly, many of the small parts are electro-pencil etched with all or part of the serial number just like the first variation single rune SS K98ks made by Steyr (bnz code).

Picture Set 1

Picture Set 2