Help with late war M1 heatstamp

[Stansuwat]

I have a rear seamed, swivel bale helmet with a M-47A heatstamp on the shell, and a liner (which I think is after market) with a M 29 marking on the crown. ANY help would be appreciated because I'm lost as to what the "M" denotes on the shell.

[ruddersrangers44]

M for McCord from the 1951 run of production.............edit,also the m29 in the liner crown denotes Marmac Industries and will be a m1 nylon combat liner produced between 1964-1972............

[Stansuwat]

I read McCord never put "M" on the heat stamp...here's some pics
imgur: the simple image sharer
imgur: the simple image sharer
imgur: the simple image sharer