reworking a fully restored car

Well, if you did not demand any paperwork as notification he recieved cash from you then I guess some of the responsibility rests on you. I'm currently doing work for a very close friend. I buy supplies, I keep the receipt for him. He gives me a payment, he gets paperwork reflecting that. At any time he can ask where I am labor hours wise and where he is money wise. I consider him as close as a brother but business is business. Everyone should take heed: anyone can do work for you - but protect yourself... and them. GET IT IN WRITING.