I have recently acquired a Kriegsmarine Mauser HSc pistol manufactured in September/October 1943 with the Eagle over M III/8 acceptance stamp, serial number 863562. It is a fourth variation late wartime pistol. The book, “The Mauser HSc Pistol” by Alan D. Burnham and Peter H. Theodore, January 2015, has been a great resource to understand the development and history of the HSc.
I am a former submariner and the Kriegsmarine connection to this pistol and the probability it was on a German U-boat is of interest to me.