Wood cars had metal roofs put over the wood roof not only for the water proofing, but for lower maintenance and to prevent fires starting on the roofs from the engine cinders. “Murphy” was a brand of metal roof kit and was used on most D&RGW cars and a similar “Excelsior” metal roof kit was installed on most C&S cars.
The Uintah Railway, which shut down in 1939, had about half of their wood roofs converted to “Murphys” when they shut down. There is an ex D&RGW car at Silverton with a “home made” copy of an Excelsior roof instead of a Murphy.