Dad,
Nice job on the exhaust. I LIKE it!!!
BWIL,
With it being a C-code (289 2 barrel engine) in 1968, to the best of my knowledge, it would not have been allowed to have the GT option from the factory. Of course some dealers did some add ons that murky the water.
With that in mind, the stripes and the fog lights were added on after it left the factory IMO. The exhaust cutout outs were also added after the assembly line.
From just the pictures, it looks like a very nice car and has some very tasteful modifications that in my mind enhance its value. From pictures it is very hard to tell the condition of the car from a rust standpoint. Based on it being an East Coast car, it is a candidate for rust, but not always if it was taken care of. But I am sure you know that.
I would take this car to a reputable paint shop and pay to have them put it on a lift and access the rust from the bottom up. May cost you 100 bucks or so, but you can take pictures and get a third opinion. With that in mind you can fairly represent to car to potential buyers. It provides you peace of mind and would allow us to zero in on an asking price.
At the same time you can market the car as is and it is buyer beware. I look at cars all the time and the ones with lots of rust are so easy to get into more than they are worth. But at the same time I have seen people buy some cars for way more than I would pay.
For me honesty is a premium and I would price it based on its true condition to an unknowing buyer. But that is me.
I own a Gold Nugget Special (GNS) with nearly all original Ford fiberglass as a GT/CS would have. And some research has identified it as a car pulley off the line and converted at the factory. But it started its life as a GNS and until definitively prove that it was pulled off the line and converted, I always call it a GNS and not a GT/CS (more than likely never). And if I sold it that it how it would be sold. A GNS with an interesting history.
Rob