orignal paint was under the hood was not that great. Not sure what the markings on firewall mean. I've seen them on other unmolsted orignal cars. Mine didn't have any numbers on right valve cover but did have the number 16 on front of left valve cover. "OK" stamp was not on mine. Maybe that was only done in sertain plants. I'm gonna go over the garage this weekend and get the numbers off vin plate and get more info on build specs for the car.