I also have a 1965 Metuchen built factory GT bucked very close to the vehicle in being discussed in the thread. My GT was bucked on July 21 (code G21 on the buck tag). My buck tag includes PIO. I've attached a picture of my buck tag with a partial VIN. In addition, I've provided a picture of the snubber plate (taken during the restoration).
I also noticed that the buck tag at the start of the post has no inspectors marks (the punchouts on the buck tag). My buck tag has 3 inspectors punchouts (denoted by the red arrows).
PS - Ignore the rear 66 style seatbelt brackets in the snubber picture. I know they are not factory (I had them installed so my kids would have seat belts in the rear seat). The car came from the factory without rear seat belts. In addition, my car also came from the factory without the rear backup lights and has the non-backup lights tail light wiring harness.
Regards,
Ron