What you tried to do is bully an honest guy who wants to do the right thing into possibly doing something illegal just because you think there's a decent chance he could "get away with it". Not getting caught doesn't mean it's right. And what does he do if he wants to sell the car? I sure as hell wouldn't buy that car without the proper documentation explaining why the VIN plate and title don't match ANY of the body numbers. One? Sure, repairs have to happen, these cars are nearing 50 years old and no one is likely to jam you up over a single body VIN stamping. But all of them?
The whole issue was started by someone like you, ignoring the law and misrepresenting the car during a sale. Maybe the last owner was the victim and sold the car not knowing any better, but at some point there was a dirtbag that took some kind of shortcut and lied about the car. There are far too many people in this hobby/business that don't give a second thought to what the right thing is. That's why there are car flippers that will slap chicken wire and bondo over a rust hole and sell the car as "rust free with new paint". Or take 30 pictures that show everything but the hole in the floor. Or swap the VIN's from a desirable car that's unrepairable onto a clean /6 car shell. Is it dumb that people will pay thousands and thousands of dollars more for a car because of a few letters on a VIN? Yup, it sure is. But it's sleazy at best and criminal at worst to take advantage of that.