First welcome. Second you can't just drop a "I have a 67 L78" and not post pics.. come on MAN!! As for the "history" of the car you may need to work backwards on the ownership trail. Usually (IIRC) once the engineering or promotional portion the car was used for; it was then issued to a dealer as a used vehicle. Others with a little more knowledge than I will post but but in the mean time post up pics of the trim tag, the car & the vin so we can help out as much as we can.