Early Flatside Contender Question

LGS has an early flatside engraved Serial number 42xxx. It as the octagona 22 LR pistol barrel and Pachmayr grip and forend. I'd say the finish is about 85%. Gunshop owner thinks something is wrong with it because if you open it with the hammaer cocked the hammer falls when you pull on the release. As I recall this is normal. Just wondering if these older models will handle 356 GNR and 44 Mag ok? If I remember corre we can't use G2 barrels on them.

Also what's a fair price?