WOW, That's great info.
It looks like Kamp King Kampers predates Amerigo
and used the name "Snap and Nap" in the 60's. Perhaps Amerigo
bought or licensed the designs from McNamee.
I do know that John Gardner (Gardner-Pacific and many, many, others) bought Amerigo in the very early 70's (c. 1971) to get the molded fiberglass technology they were using and started building the first Sunrader molded fiberglass campers in 1972. A few Sunrader campers were built with the "Snap and Nap" feature using that same trade name.
Now, for the ultimate camper, everyone that read this far, take a look at this link: (scroll down for the original ads.)
The Camper | POWEXPLORER
There seems to still be a few of these behemoths around.
Are we havin' fun yet?