If th engine # match go for it and spare no expenses on the body work. I have a 1964 SS 409 with air,auto,pwr sterring,pwr brks ,pwr wdws and locks . $40,000 spent on correct restoration and it is worth $200,000 + $
Unless you're really, really good with tools and your hands, I'd suggest you don't try it. Even though I would ordinarily say, "Go for it!" to anybody who needs help restoring, reworking and/or modifying any old car, since you're asking about "costs" rather than the actual work, I am assuming you're in over your head. Forget about it and either pay for a professional or sell it to someone who knows what they're doing! Sorry to throw a wet blanket on your fun, but it is not for the "faint of heart" to restore a vintage automobile. Body work alone is a skill that you have to be taught, not learned by trial and error and as for the engine rebuild? I'd just buy a crate engine and drop it in, rather than rebuild an unknown entity. Thanks for the two points. Good luck!