You'll be disappointed by how many parts and pieces will not interchange.
Reproduction parts catered to 57 Belair, then early Camaro and early Mustang long before these fishes. That simply means that majority of those examples have all been restored atleast once. I do see a 65, 66, 67, 68 beater grade Mustang in the street once in a while but.. I can tell they were once parts donors that have been pieced together / resurrected.
Now that a heap of fish parts are reproduced, many vintage drag raced cars are being reverted back to street rides. Even that is more practical than donor resurrection.
The good news... It's not too late to buy a decent fish and restore it. Get what parts you can from one of those part yard donors. The route you are thinking is still about 10 years from the only route. As a follow up question... Did you see a Belair, Camaro, or Mustang, in that yard ?