I own two Steyr Mannlicher-Schoenauer full stock carbines, both in .270. One is a Model 1952 with a non-Monte Carlo stock and the other is a Model 1956 with a Monte Carlo cheekpiece. Both appear original, but the M1956 has a bright bolt and handle while the M1952 has a blued bolt and handle. Has one been altered, or is this correct for these models?

My memory is certainly not what it used to be, but I believe those are both correct; the 1952 was the last of the blued bolts on traditional M-S rifles and the 1956 was the first of the polished ones. Both had swept back bolt handles, unlike the pre-WWII models.

IIRC the polished bolts were intended for U.S. consumers as the Europeans preferred the blue bolts. The 1956 MC and 1961 MCA were meant for the U.S. market while the GK and NO were popular in Europe. From 1952 on the metal was all the same with only the stocks differentiating the models.

The Model 1950 and Model 1952 retained the blued bolt assemblys of the pre-war guns.

The 1950 retained the straight bolt handle shank.
The 1952 went to the swept back bolt handle shank
Neither has a M/Carlo stock.

The Model 1956 had a bright polished bolt assembly w/swept back bolt handle and a M/Carlo style stock

Thanks for the info, guys. That confirms that both of my M-S's are original. Both are in great condition with the exception of being missing their sight hoods. The M1952 is just as you would expect it. But the M1956 has a surprise: A factory left-hand Monte Carlo cheekpiece on a RH action. I suspect there aren't very many of those floating around.