After Bela Sztanko stopped returning my messages, I elevated my Paypal dispute to a "claim." He promised to send me an early SC fuel distributor, but instead shipped me a late SC fuel distributor with a bolt driven into the frequency valve port.
Paypal apparently does not consider disputes related to the attributes or quality of the goods received. It's only a $150 claim, but I'm very disappointed that someone who sells this volume of parts on Pelican (he's always got ads over on the Classified Board) would refuse to make this transaction "right."