G503 First Aid & Gas Casualties Kits
progression of First Aid Kits was:-
segmented stock number is 100% post-war.
Yes, I believe the U.S.M.C. kits are Marine Corps. Despite references to "Corps" that may exist, the official acronym used on WW2 Army medical gear was U.S.A. M.D. Check out the medical section in Government Issue (for example) and you'll see the use of U.S.A. M.D. markings or, better yet, the 1944 MED 3 Supply Catalogue. The relative scarcity of the "U.S.M.C." marked kits would correspond to the relatively limited production for an organization considerably smaller than the Army. I think they represent the early kits based on graphics, piano hinge and paint finish and were probably replaced by another style for the remainder of the war. JH
The progression of First Aid Gas Casualties Kits was:-
Various Clasps and Hinging
Some Manufacturers Names are :-