One other option is you can clean up and paint the engine bay (and possibly interior), and leave the outside patina'ed. Seen that done on numerous vehicles.

1949 Chevy 3100 (In the family since new)
1955.5 Chevy 3100 - in the DITY Gallery - (Dad's truck)
1955 Chevy 6500 - in Big Bolts - (Possible parts truck?)
1958 Chevy 3800 w/9 ft bed - in Project Journals - (Current project)
1959 Chevy Spartan 10400 - in Big Bolts