I'm with Nick on the final.....the side by side with the WWII lid shows an absolute shorter dome height. That along with the heat stamp (have you determined if the first digit was a number "1" or a letter "I") seals the deal. There were no 5 digit McCord shells made during WWII and all the Schlueter lids (well most any way) had an "S" stamp. This does not fit the 5 digit heat stamp you have provided making it almost certain to be a 1960's or later lid.
I appologize as my response was misleading...It should have said painted for KW use; not repainted (as though I was implying it was a late WWII lid repainted for KW use).
The paint job in the original photos looked dark which lead me toward KW use; now seeing the profile compared to a WWII lid, I'm also inclined to say 60's VN use, as Nick and MSD have already stated...
Just for info not necessary pertaining to this helmet but there are rear rimmed helmets that have stainless steel rims, they are not uncommon. I had two M1C para helmets. Sold one and still have one. Both rear seamed and stainless rimmed. One is featured in a helmet book. And there are front seam helmets that had magnesium rims. Helmets put together in November/December 1944 were in transision and had both types of rims. Ray