The original poster never got an answer to his question.
Not sure of the question he asked a little over four years ago. Reading through his posts I see a report of what he found followed by additional pictures and findings. Looks like the discussion took a right turn to discuss early 65 production
Are you referring to the "So is it likely that I have a real GT?" Possibly but since the car has been altered over the years no way IMHO to tell from a distance
Is there something ' GT ' about his pinion snubber plate and bumper that the other models didn't have ?
Differences but not related to the GT package
Is this another method to identify a factory GT ?
The determination is made IMHO through a process of discovery and findings including what should be there and what should not be there. No one or even a dozen things that would prove to a certainty. And if there was posting a full list publically would also serve as a guide to those wishing to convert and possible deceive others
Just an opinion and concern