If the guy you dealt with is legit, I bet the way he was going to work it out with the customer was to do some work for him outside the shop.
Hopefully, the wheels weren't stolen, but at least now you don't have to be concerned about that.
As I was reading through the posts and saw you decided to take them back, I was hoping he wasn't going to scam you by giving you the old "Oh man, I'm sorry but I didn't have time to get by the bank, and my boss won't let me leave now... is a check okay?" when you got there.
And then the check doesn't clear.