Or maybe the door is from a '67. The rest of the car sure does look '68. Have you looked for broadcast sheet, or look at the VIN stamped on the rad support. Something is "Fishy" pun intended.
Where exactly on the radiator support. I looked at it today and did not see any #'s. I was told the build sheet in under the rear seat, but when I pulled it up I did not find any build sheet on the floor of the car when I removed the sheet. I agree something is "Fishy" going on here....