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.
This ^^^^^^^^^^^
Pic is after a the truck was park for 30 plus years in field in SD. It was completely green when parked.
When parked it had a complete wood bed. When I rescued it all the wood was completely gone.
Complete overhaul engine, Trans, drive line, brakes, chassis, electrics of every nut and bolt.
Cleaned and 3m pad with diluted CRL then 5% gloss clear.
