The Supergrade Fwts are so rare that hardly anyone has ever seen more than one in their life. I only ever saw one that I remember myself, and it was a 270 with a pad as well. It was priced right but no one would touch it.
This was before the internet and affordable CNC machines, and the chance of finding an un-molested Supergrade Fwt stock was slim to none, and that is why no one wanted it.
When I first looked at the OP's pic the cheekpiece and monte carlo didn't strike me as anything that odd. It looked like an older cheekpiece on a later monte carlo. With a gun so rare that blend of old and new doesn't surprise me; nor does the older barrel and again for the same reason.
In a related note, today I handled a beautiful 264 Win Mag Fwt and a very nice nice 1962 375 H&H. The 375 had beautiful wood and the small machine checkering panels were recut to mid 1950's. They did a nice job but not perfect by a long shot. I didn't look at the serial of the 264 the beautiful blueing on the barrel and gorgeous wood dominated my attention!
