Just to elaborate, I never doubted the authenticity of this Yenko, we just wondered what happened to it. It was a VERY nice car. In retrospect, I believe the guy was a little defensive because he really didn't want to sell the car at that time. This was 1981/1982, and we discussed the possibility of these cars skyrocketing in value someday.
I do not recall a Yenko in Lisle, Illinois.
The people around this area probably remember the Yenko Deuce parked behind a repair shop in Westmont on Ogden Ave. as well.