Don't know the guy. But you said there is a warehouse full of resto projects somewhere in the middle of restoration. That may be a factor. Maybe this guy has too many projects started and is therefore unable to complete them. I've read many stories about guys who have their car in paint shop jail. And have no idea when their car will be completed.
Has or will this guy give you a written contract w/ a ETA for completion? Is there any penalty for his failure to meet milestone dates? I'd hate to give him money and then the car is shuffled to the rear corner of the warehouse and not worked on.
Just some thoughts. Good Luck
Judging solely by his Face Book page it looks like he is swamped with projects. So unless he has a large staff your Camaro could be in the shop several years contract or not.