I believe, after speaking to Bill, that it was there as M82 because it fell in the sequence of numbering at PH at the time, but Roger Hale clearly never filled it with a "real" rifle.

I went through the records, and there is absolutely no recording of what can be called an M82 in the registers, lots of (prototypes) but no M82's.

One would therefore suspect if indeed there are a small few out there numbered as such they would bring a good price!! Bill might dig up some more info.