UPDATE:
Well, I got the Marti Report on 8R01J156978, and it is an Acapulco blue GT/CS that came with a four speed, adjustable mirror, front seat headrests, PS, AM Radio, F70X14 wide-oval WSW tires and deluxe wheel covers. It was ordered by the Seattle district.
Interestingly enough, the car has the larger front sway bar, the heavy duty rear springs and the dual exhaust lower rear valance panel, but is NOT identified with the GT option!! I compared all of these items with my 1968 GT and these items on the GT/CS match the GT perfectly. Interesting!!!
Also the car had leather covered front and rear seats that appear to be original, but I have never seen this in any other 1968 Mustang, so I'm guessing it was insalled later, but it is quite a nicely done, professional job.
The car sat on the lot for over 5 months after its production date, in fact it did not sell until 9-13-68, just about the time the 1989's were coming out!
Russ