"Let the buyer beware" indeed!

Its completely reasonable to want to have a 30-year-old auto checked out by a professional. There are simply too many things that can be overlooked by an owner or a potential buyer looking at it in the driveway. She needs to understand that unless you can verify that any part is in good order, you must assume that it will need work and the price of the car should be adjusted accordingly! Would SHE buy a car like that from a stranger and just take their word that it "ran great"? If you're going to pay top dollar you've got a right to know if you're getting a top-dollar car. If she doesn't agree, there are others out there. The right car/seller/deal will come along. Good luck!

PS I have a 50-year-old Swiss driver's watch for sale that also "runs great"-if you consider gaining 5 minutes an hour running great!