There were a few people I knew that had these cars. Most of them were probably in your dad's group. If I can remember correctly, these were called Keene Cars and came from Keene Sports or something like that in or around Bakersfield, Ca, probably Keen, Ca.
I think the frames were made for them by San Fernando Buggy and looked like a rear engine version of a sand sprite 4. I never saw a blown Keene car but I also never saw one that didn't run on methanol. They didn't have a cooling system, the VW was cooled by the methanol from the inside. I believe most of them were 2442 cc and if they weighed more than 600 lbs it would not be by much.
The Bakersfield Boys really put on a show when they showed up a Dumont. They were like a sand rail drill team. The Vegas group could put on a good show too, one guy who I can't remember his name but at the time had a gas station on Sahara and Teddy Dr. was one to watch. Wheelie down comp hill, grab the steering brake just before the bottom and wheelie back up with the front wheels in the air the entire time. As far as pictures go, the only one I ever took was of Chuck Bartolo and I gave it to him.
Randy Black the casino owner and condo king (Rock Springs Vista) Was on the front cover of Dunebuggy and Hot VW mag doing a no-hands wheelie up a hill at Coral Pink dunes in a Keene Car. This was probably around 1982 or 1983.
Ahh, yes the good old days at Dumont.
Big D