As I keep digging and digging, I came across this forum, and a thread dedicated to the paper models from the above magazines
Dr. Fate & other paper model slot cars | Coffin Corner 2
and I was surprised to see Dave showing interest, and the actual built up cars, and an additional issue, February 1968, the Christmas tree and Timing Tower
There is also mention of panels that could fit into the Hot Rod van I found some time ago, and a related Big Rig hot rod out of the August 1976 issue of Car Toons.