Hi,
If I recall correctly, Universal owned Dan Markov's Eureka. It went to wild west town that was still-board (fire burned the enginehouse down around Eureka) and Dan rescued her.
I do not know if Universal still own's a locomotive. The wood copy of RGS 20 for them hauling the locomotive across the mountain is back to Durango. I think it was used in many TV shows. For instance, Petticoat Junction used Sierra RR #3 for the moving short, but the close up shots were using the Tomahawk & Western prop for the cab.
Doug vV