I recently bought this USAAF A-10 (or possibly A-10A) summer flying helmet. There is no label inside it, although it is stamped '1941'. It also has another stamp which is over the top of the circular USAAF stamp on the inside of the helmet! I believe this is some spurious made up 'German' stamp (not least because the swastika is facing the wrong way!!!), however, just to be on the safe side I have posted it just in case anybody recognises it.
It is also interesting to note that the raised pattern / serial numbers on the ear cups have been cut off.