Greg,
I have not been able to find any pictures of the consist you describe.
One thing I can tell you is that in all of the C&S excursion photos I have here, there are no smooth, round roofed coaches in any of the consists until 1960, when I found one.
The C&S coaches used (4) in excursions in all previous excursions I have photos of here, all had a raised clerestory roof.
In the one 1960 shot, the smooth roofed coach seems to have "Burlington" stenceled on it, but so did all the C&S cars.
I'll keep looking, but I don't think I have aything else here that will help you. All Dad's negatives are in Boulder.