Just measured my '70, I'm guessing it would be the same.
Mirror to mirror: 6' 4" (76 inches). How I did it: taped one end of the tape measure to the left mirror's tip, went through the interior to the other mirror's tip, then added 1/2 inch each side for the slight inwardness of the tips.
Bumper to bumper: 15' 6 1/2" (186.5 inches). How I did it: used a level at the center of each bumper and marked the garage floor, then ran the tape measure under the car to each mark.
P.S. Welcome back and good luck with your new car.