Ouch! :( As a lifelong Corvair lover, this makes me sick to my stomach.
Do you have Antique plates or similar on that car? In my state, if you have normal plates, the other guy's adjuster would go strictly by book value and total a car that old without a second thought and force you to scrap it, give you book value, or get a salvage title... and no more collision or comprehensive coverage. That's what happened to my mom's '91 mint Crown Vic wagon in 2010 (insurer paid us book value, let us keep the car; we used the money to fix it but are forbidden to buy any coverage except mandatory liability).

When your car gets to be 25 years old most states will issue Antique or Historic Vehicle plates. They do limit your driving to club events, parades, cruise nights etc. It can't be your daily driver. The good news is you can get special insurance from Hagerty, J.C. Tylor, Grundy or a host of other specialty antique auto insurers. They also restrict usage, but you can usually get "stated value" insurance to protect your investment. The best news is it is usually quite reasonably priced...