1911 Frame Markings

[UpperAtmosphere]

I picked up a Navy 1911 that dates to 1918. Most of the markings I have figured out easily enough.

JMG on left side of frame = John M. Gilbert

United States Property = fairly self explanatory. Font looks kinda like Wedge Gothic.

Top of the frame, just north of the magwell has a little 8 stamped.

Top of the frame, just north of the disconnector hole has a little H. Provisional acceptance mark.

Top of frame, just south of the disconnector hole has a little G. Indicates government contract.

Now, the one I can't figure out. A hair east of the provisional acceptance mark is the letter M.

Various 1911 sites list a lot of frame markings, but not that M. Any ideas?

 

[Jim Watson]

Clawson sez a letter at the location of your "M" is an assembler's mark, unless yours has one on the trigger guard where it was moved in late 1918.
His example is an "R" but obviously they had more than one assembler. Somebody posted an assembler "L" recently.

If there is an assembler's mark on the trigger guard, the "M" is probably a Colt company inspector.

 

[UpperAtmosphere]

Thank ya, sir!