I doubt those hood bumpers are original, they are the earlier squared top. Although, I have seen the open style used up through mid-April on Metuchen cars.
Right, I think the car has some questionably early parts on it that probably weren't original.
For example, it has:
Clip on window cranks, the early manual shifter bezel, square corner sill plates, early hood bumpers. It does have the early style fastback deck lid, though I guess that could be correct for a '65 model. It also has the later blower motor switch, not the one with the center position being "OFF". This one has OFF at the far left position, like a later car.
I did check behind the dash, and the car has the correct half moon cutout for the GT-style speedometer. The cutout was factory--it was very neatly done, just like the 1966 style dashes I've seen, with a small lip around the cutout. The instrument cluster also had the correct '65 ammeter loop wiring harness. I couldn't see where the dash harness had ever been out of the car. I also checked and the taillights come on when the fog lights are turned on. Finally, I looked under the rear seat, and the reinforcement plates are there for the dual exhaust.
At this point, I still think the car has some features that came from another/earlier car, but there's no doubt in my mind that the car left the factory as a GT.