I just picked up an M1 Carbine, IBM receiver, underwood (11-43) barrel, mixed internals, M2 stock and bolt. My question is about a Line punched through the words IBM Corp and a large N or Z stamped on the back of the receiver under the serial number. Anyone know what this is about?
It has greenish parkerized look on all metal except for the mag release and the bayonet lug/barrel band which are black.
I would imagine they bought the receivers to fill an order on time, not sure. Probably why they used other manufacturers barrels, too. Although not common, not rare either. If the gun was all original, the lineout would probably raise value some.
Larry Ruths' book WAR BABY! would probably have lots of info on it, although I don't have it. Maybe someone here does, and they could provide more info.
No link, I just remember reading it in "U.S. M1 Carbines, Wartime Production" by Craig Riesch. Although not perfect, it is an excellent beginners book, and cheap.
You could also ask the guys over on milsurps.com (M1 carbine forum). Very dedicated group of carbine collectors. They could tell you much more than I, and probably more than Ruths book!