I'm in Falls Church and have a '63 Impala convertible. If you need something, I'm willing to assist if I can.
Just one thought. Before I would begin spending money on the car, I would recommend you give it a through inspection looking for ALL the rust. Get it up on a lift so you can see under it. Pry, gouge, poke, scrape, (whatever) the frame and body and all the areas where the rust may occur. Remove sections of carpet to look at the floors. Get into the trunk too.
If you have to pay someone for body work, you are looking at LOTS of $$.
My '63 had zero rust anywhere but it did need a paint job (the existing one was not properly done). For a 'new car' quality paint job (not at all fancy); including removing/replacing all the trim, repairing all the little dings and dents was $10k.
I addressed the body work first because it's probably the most expensive stuff to 'restore'. But while you're 'inspecting', I'd make a 'list' of all the restorations, replacements, upgrades, repairs you might want/need to complete. Assign a value to each, and see what you're 'in for'. Double the total. Then figure that's the bottom of the range.
You may have done that already. I'm not at all trying to discourage you. One can enjoy the process immensely.
Attached is a pic of my '63