Does the vin on the door match the stampings on the body? If so, then at least you know that that number is legit, except for engine size and body line. Then go from there. Is there a fender tag? Does the door sticker look original, or new? If everything seem like it is really a RR and the state says it's not stolen, then go from there. Down here I can get a title for an old car without any kind of paper work.