I've looked at a 1967 GTO on the ebay and called the seller and asked for a pic of the data plate to see how it was built. He says the data plate was gone prior to his obtaining the car, and a picture showing the firewall on his website confirms there is no plate. He states it is PHS documented based on the VIN plate on the door jamb, plus it it titled with that VIN. Obviously the car isn't original as it has a 389 in it. My question is, what are the concerns and issues one might have with the car not have the data plate? Thanks.