I’m going to sound like a geek, but the lime green was the Palm Beach model, not usually desirable, louvered blonde wood cabinet doors that tend to squeak. The red velour was a special edition Coca-Cola model, gaudy but highly collectible. A ‘78 Royale with the right interior layout is top of the heap for people who actually use them, here are photos of a really nice renovated one for sale in Ontario, CA for $22,500:
http://www.gmcmhphotos.com/photos/g4931-1978-royale-enhanced.html
Love the walnut, lol.
Perhaps I should start with researching the one that holds the RV land speed record from Bonneville...