Agree to disagree. I don't know how old you were then, but I was there, then, and had just gotten my driver's license. I distinctly remember the badges in front of the doors. And it has nothing to do with GTS emblems. I bought a new 68 GTS in 68, so I was very aware of these things.
I agree with the previous comment about pre production press releases. I remember the infamous pictures of the 71 Challenger T/A, which was never produced.