I didn't think the Kansas City Plant used the 5N code to denote the GTO package. Only two of the five plants did, one of which was the Pontiac plant. I have to agree with Rukee, that the putty does look odd and I've not seen too many other data plates with putty in the rivets. The seller did list the RA option as dealer, which is correct; as 05GTO said, it was not a factory option in 64 or 65 (or 66 I think). Didn't come out as a factory option until 67 if I'm not mistaken. Still, it is a nice piece of work that someone put a lot of time and money into. Whether it is all original is another matter. I dread the day GTOs fall under the same scrutiny as the NCRS Vette set, but I see it coming.