Well Rick, you hit the nail on the head. It was one of Mr. Chivovetties boats, (red and black with twin "Experimental" motors). I know for sure that it was not built by Scorpion, whic incidently was a poor splash of the Challenger. It had the pre knotched bottom.
I have heard that it was bult by Charger, which makes sence because they also bult the Linder designed 18 DL-----also one of the greatest boats designed.