Rookie Mistake...
If he goes belly up and the car is on the property it will be hell to get your property back.
^This^
I've known guys that have gone through that scenario and it's not good. More money (lawyers etc.) on top of bad... and you'll never get all your parts back.
One of the problems for a lot of shops is the owner is either good at bodywork or a good businessman. Rarely does both come together. Throw the ex-girlfriend business into the mix along with your substantial down payment and it's just a recipe for disaster for everyone involved.
Sorry to say if you're going to lose $4k on this mess, consider that gone and yourself lucky that it's not more.
One thing that bothers me is that he has removed the VIN tag. That may blow up in everyone's face when you can't just walk over and look at the VIN tag to prove the car is yours. Since it's a '68, that VIN isn't going to be stamped in the body like the later cars. The sequence number is and that's on the fender tag, but he has that too. In other words, you may want to think long and hard about calling the cops to be there when you pick up the car... If there's a problem, you can call from your cell phone...
What I would do is just show up, be nice... and just say this isn't working out. NO EMOTIONS, even if he gets a little pissed. Just be nice and straightforward and take everything in one trip. Some friends to help is good, just remind them "No emotions" to keep out of a fight that would be in HIS shop.
