3.
^^This. Intent is everything and since nobody can prove intent, well....
Buying ANY used car is an "as-is" affair. Buyer beware, do your due diligence, etc.
I hung out on the old eBay Motors discussion board for several years and learned a lot about such matters, especially from the dealers/sellers who also hung out there.
The common threme, time after time, were hundreds of cases of "buyers' remorse" just like what the OP is describing here:
1. Somebody decides they want to pick up the ride of their lives, gets their heads all full of rosy notions that 50+ year old cars drive and run really nicely and without issue like modern ones, and plunk down way too much money for something that looks really great in an ebay ad, usually without either checking the car out in person first or hiring a mechanic/inspection service to check it out on their behalf.
2. They might actually sometimes actually contact the seller (you'd be amazed how many people drop tens of thousands of dollars, sight-unseen, on rides and don't even bother to call the seller!), who is going to naturally paint quite the rosy picture of the car. Buyer takes that story as gospel because well, you know, they want to believe.....
3. The big day comes and the money changes hands and the buyer takes possession and reality sets in. All the warts and niggles of the actual, real-life car present themselves and the buyer feels duped, so they start hollering "fraud!" as the reality of their paying way too much for a car they didn't properly research sets in.
They expect the seller to own up to some real or imagined wrongdoing and to give them some money back. Yeah, right.
Again... behind all the fancy online ads and beautifully written descriptions, beyond the fantasy that there's tons of B-J show quality cars out there for eBay prices and beyond whatever fluffed up promises the seller offers....
What you're left with is the purchase of a used car, usually between two private parties.
The common sense rules apply - do your due diligence, have the car professionally inspected if you can't do it yourself BEFORE you place a bid or make an offer.
Don't get into bidding wars and pay too much.
Finally, accept and understand that ALL such deals carry the understood "as-is" descriptor.
Don't buy a pig in a poke and once the deal is done, don't get all "buyers' remorse" and drive the seller crazy. Honest, deceitful, whatever, money changed hands, deal is over.
As the sellers on EBMDB liked to say "enjoy your new car!"