Ok, here's what worked for me...
Get a couple of screen shots off of the TV show. Then start running RV Wanted Ads in all of the Craigslists within about 500 miles of where they were built. Put the ad in the RV For Sale
section so more people see the pictures.
Offer two different "Rewards" Maybe $100 for information leading to finding one and raise that to $200 if you buy it. Be sure you put a phone number in your ads. That has worked for me in the past when I was looking for Fiberglass Sunrader motorhomes. Located three for sale
With only 40 built, and they were very expensive, most were probably sold close in to the factory. Give it a try, the ads are free.
I'd even go to the local newspapers and see if they want a local interest/local history story. Make a big deal of your search for some of your towns famous ideas that were just 50 years ahead of their time.
You might also try to trace down any remaining family members of the builder, they may be happy you help you find one to restore. They may even still have one....cool! You May be able to get some family leads off of Ancestry.com
But I got to warn you, if I find one out here in CA you will have to wait for the second one to be located ...LOL