Above you can see the condition of the roof better.
I wish I remembered more, but I can't recall anything. If you'd like to know more, you can get ahold of the Motor Transport Museum http://www.motortransportmuseum.org/
and see what they can tell you. I'm sending an email myself, and see what they can tell me (which I should have asked when I was there but was stunned at the variety of things to see)
"Any and all photos taken on the museums property must include the wording: "By permission of the Motor Transport Museum, 31949 Highway 94, Campo, California, web site: http://www.motortransportmuseum.org"