The Rebody Police will be all over me but I think if you document with lots of pictures what you are doing & stamp your new cowl or transfer the numbers section of the old cowl to the new one with documentation I see no foul. If the core support is original it should have numbers on the top or radiator side closer to the drivers side. Is the door vin sticker still there? Front spring hangers boxed? Do you have 2 steel lines running from the fuel tank to the fuel pump? I would use whichever screen fastening type holes that the car has now! GTS