Very interesting trivia - I've never seen one before. What are these worth?

That all being said, I was living in Chi-Town area back in 1979 for a job - I lived out there for about 5 months. I remember a Dart GSS at a transmission shop - the car was parked outside. It was black & had the Paxton supercharger on it - one of the guys there showed it to me. THAT made enough of an impression on me that I still remember it today! Seeing one like that "in the wild" so to say.