CRRM is looking into it.

All I did was find a picture of the West Needles and comment that it looked similar. Two others had recognized the location and David Borders saw that it was reversed. It now looks like a dead ringer!
I called Kenton Forest at the Colo. RR Museum to find out if they have any drumheads or any good pictures of, say, the Shavano's. He said all they have is the Scenic Limited's (1940's standard gauge). They are looking through books and materials to discover anything else. I would assume the Shavano's center was a picture of Mt. Shavano.
The reverse image would make sense if it were painted on the inside of the glass to protect it from the elements, but you say it is a film of some sort? Maybe they just got it in backwards. Do you think it started out as a photographic slide then got painted over?
After looking through the CRRM's Annual #24, I noticed a couple of things. First, there is no picture of a Narrow Gauge drumhead in use before 1942. I would have assumed that they were carried after the 1937 remodeling of the passenger fleet. And I would also therefore assume that they only used electric lights. Second, there is a drumhead photo showing the outside ring in reverse colors. So I wonder how many there actually were?