Mike,
Interesting info, but here is why I think the cars in question are D&RGW cars used by the CB&Q:
The two steel framed, ex C&S cars from Heratige square (Magic Mountain) came from the Rio Grande Southern. They were bought by the Narrow Gauge Motel when the RGS was abandoned. Following the parting of Bob Richardson and Mr. Heflin, the cars remained in Alamosa and were then sold to Magig Mountain. Magic Mountain removed the original bodies and made new "passenger" bodies for the cars. These two cars are now on the Georgetown Loop, one in service & one stored.
Cars 5,7 & 9 (the Railroad Fair Gondolas now at the loop) were purchased from the Black Hills Central by Lindsey Ashby for use on the Colorado Central in Central City and were then moved to the Loop. Folks at the Loop belive these cars were used by the CB&Q at the Chicago RR Fair, because the C&S had no more narrow gauge cars in 1948, the Rio Grande provided them. Since the Rio Grande was converting some high side gondolas int passenger cars for their own train at the RR Fair, it would make sense that any they provided for the CB&Q/C&S would look the same. Photos from the Black Hills Central, Colorado Central and Georgetown Loop confirm that these are the same cars and that they look the same as the cars used by the Rio Grande and CB&Q at the Chicago RR Fair. (There are postcards from the fair showing C&S #9 pulling a string of converted gondola passenger cars that look exactly like the ones in the aforementioned photos)
The photo I have from Hill City shows 5 of these cars, and they all look exactly the same. 3 are now in Georgetwon, where did the other two go?
Jason Midyette
