DMV rule is (read: rule not law) that the seller is to provide a smog cert when sold. If you bought the vehicle without asking for the smog cert, you bought as-is. DMV is not going to enforce any rule after a sale. Your recourse is to fix it and smog it so you can register it. Then file a claim in small claims court against the former owner. He will argue you assumed liability for the smog when you bought it as is. It's 50/50 if a judge will act as DMV's agent and award you anything. I've bought and sold many vehicles without a smog with the understanding by both parties the sale is as-is.
BTW, What did the 87 Minnie fail in the smog test?