Newbie, Thrown Into The Luger World By Accident

[day late]

Originally Posted by Edward Tinker

I moved this from the Tech Help area to new collectors.

Yes, the 'm' suffix is part of the serial number, but afraid it has nothing to do with the navy.
You have a 1936 (date) that likely has the Mauser code of S/42 and made by Mauser.

It is stamped S/42, so I guess the M does mean Mauser. One marking Which has me puzzled is inside the frame, under the lockdown bolt. It is quite clearly stamped H. I have no clue what that means. I've looked on-line but haven't found anything.