So I've had this one for awhile. Bought it from a rummage guy who said he found it in the trash not too far from fort drum in New York State. I have seen similar lids from the Vietnam era painted white for hate security, but not with slight oxidation and rust... Could this have been a navy helmet? Navy had all sorts of crazy helmets, and I haven't seen post safety painted on any helmet when searching for images, more or less all white or a liner with decals. Heat stamp is 9125.