Okay Herb, you've definitely detoured at least a few of us down some "lesser-traveled rail-lines of the internet" this morning, that's for sure....
....but man.....the scenery is great
Your Centurion listings got me hunting for more great info/photography of those things from back when they were new....and ended up stumbling across this neat "curbside classics" article on the "Cabriolet" E-series conversions, look essentially identical to those Centurions.
Curbside Classic: 1990 Ford E-350 by Cabriolet – Purpose-Built Fifth Wheel Trailer Hauler
But wow.....its what THAT article made mention of that was truly awesome: has anyone ever heard of the "Ultruvan" conversion, built by a guy named Steve Divnick? Apparently it was the first one of these "pickup / van" conversions ever.....and started the whole trend.
(The idea of which was then picked up (pun intended) by Centurion and other custom builders, who made a whole mini-industry out of it.)
Hot damn this thing was cool (check out the rear-swinging double-doors into the truck bed, and the mod interior lounge space).
Article detailing it's build --- man, this guy was definitely dedicated to the cause.
Link: The Ultimate Truck-Van: UltruVan
This guy seems like he was cool as heck.
"While a school teacher, I designed and built the first prototype Pickup-Van combination, which later became a standard in the RV industry as 5th-wheel tow vehicles. It was featured in a number of magazines in the late of 1970's. It has always attracted lots of attention whenever I have taken it out for a spin. On a trip from California to Michigan, I got out of a speeding ticket because the highway patrolman became intrigued with the conversion.
With a young family, I wanted a pick up. But I also wanted a van for its obvious benefits. Since there wasn't any vehicle like that on the market, I decided to build one.
I knew how to weld, having built off-road racing vehicles, trailers, and other projects. But this was the most ambitious endeavor in my young life. It took many hours over a two-year period after school and on weekends."