There are lots of way you could have had the car inspected prior to incurring in your words "considerable expense" A plane flight out, a local member. How is this in any way GTX's fault that you incurred the expense. It's part of the cost of buying these old cars. It's also unreasonable to expect, or in this case, "guilt', a seller to eat ANY of that cost when they haven't done anything wrong. It was your decision to bail.
After reviewing pictures and having your body guy say it was cool, YOU decided after viewing the car it wasn't what YOU wanted. Sounds like a breach of contract to me. I know the car was not misrepresented as to condition.
I think if he didn't say anything to you when you reneged on the agreement you were lucky. I would have told you straight up after making this statement:
You'll get back some if any of your deposit after the car is sold and not a moment before. Any deficiency and expenses would be withheld from your deposit as liquidating damages. It's just business.
You used your deposit to, in effect, hold the car until you got a better look at it... Not cool. Been around long enough to read through the BS and get the real meaning. hemicop, I truly get the feeling it's "all about you."
Bottom line - you breached the contract and now must wait until it all settles out.