Here is a comment I just got from Jon Speed:
" By the way I saw the small talk on Nitro site about the 7X73 von Hofe rifle and wanted to add that the action on this rifle had been a Single squre bridge soild left wall example but on many von Hofe rifles the rear bridge was milled down to set up suhler type scope bases.This was also the case on some Halger rifles as these groups did not consider the Mauser square bridge scope mounting strong enough for whatever reason."
I disagree slightly with friend Jon on the last sentence only: Imho they did not want to buy Mauser's proprietary rear rings that only came in more or less standardised sizes and heights. So they removed the square bridge to be able to fit Suhl made, f.i. by A.W.Triebel, claw mount bases and rings. Noone of their then customers cared about "collector grade originality", they only wanted a reliable, strong, scoped rifle.