Brother of previous owner wants his car back! What to do...

This is one of the most confusing threads I've read in a while.

Best I can make out is you posted on here for a little hand holding because you traded a running, driving, clapped out, nothing special Duster needing major bodywork (properly hanging quarters on any car right is a HUGE ordeal at best, requiring skill, patience, and more than just a few tools and equipment) and 3500 cash for a late 60s Barracuda "race car" thinking you'd cut a fat hog and now you need to unload it for cash?

The PO's brother is miffed the Cuda "got away" and wants to make a deal to trade the previously owned 6 cylinder Duster to back to you for the Cuda after he does paint and bodywork instead of cash.

You're estimating you're in the Barracuda around 4200 and have a verbal offer of 4700 cash but nobody is showing you any money.

You obviously have no interest in owning the Barracuda so do yourself a favor, tell the guy that made the cash offer to put up or shut up. If he's really interested he'll bring the money over. If he shows up, take the money and run.

If he doesn't, make an ad up with detailed pictures and description and advertise the car nationally. Ebay, Craigs list, car forums, etc. If a lot of people know the car is for sale, someone will eventually make you a legitimate offer. Keep dropping your price a few bucks at a time until you sell, and you will have found the true current market value.