One has to remember that all of the Santa Barbra actions were prefixed by C/P/R/S and all arrived at PH works in Birmingham. It was there that the SPAIN was ground out on the Tang. If you take the stock off you will clearly see this grinding on the opposite side to the bolt.
Fascinating times even the C3's had the same treatment on the Canadianrefurbishment contract, but one consistant thing was they were all .308's.
Its a good price if the bore is sound.
Personally, I would speak to Richard Stork at Devizes guns on 01380 727282, I know he has a few PECAR scopes in, and unless we can prove provinance of the scope to your M82 rifle it matters not and I know his will be a fraction of that cost certainly between £150-£200.................only a phonecall away. Let me know how you get on
Later: Just found a link on his site to a PECAR scope with good optics: Scopes, Mounts and Rings