Fuhrmann, I know Peter personaly and he put an incredible amount of work in this U.S. patent list and more anyone can consult this list for free, many thanks to Peter.
I visited the web that you mention and yes this is one of the survivers after the WW II like W. Brenneke who have his shop in Langenhagen. Furhmann, I agre with that that the patent is "different" from the pictured gun at E-Gun. I also not find info on this type of drilling in the Waffenschmied or Waidmannsheil issues that I have from the GGCA
Marc.