Someone went to a lot of effort to make these, but blew it when they put on the letters. These appear to be castings that have been tumbled and some finished machining. I'd guess they came from a foundry in India. True test is, of course, a Rockwell Hardness test to USGI spec of 15N 89 min. Original USGI hammers were case hardened, hence the superficial N test, vs a standard Rockwell C. If they have been case-hardened, then you only have a very expensive good looking replica, (except for really bad stamping, almost look electro-etched.

It is certainly a shame people sell these (greedy con artists), and worse, someone buys them, thinking they are real. Are these Ebay buyers going to pass these along as genuine in the internal workings of an early issue carbine?