of all of the things mentioned the 3-speed wipers are most likely going to be there and posibly the 26" radiator opening. The fuel and return line, the oval filler neck hole, head rest, and for sure only a heater firewall, NO A/C firewall! If it has original fenders then the 383 callout emblem holes were never drilled, and the fender hood pad should have the hole enlarged for the front hood pins. No 3-speed wipers, 26" radiator or oval filler neck hole you better look closer IMO.....oh, and an A/C firewall and the claim it's an A12 then