If you can't find anything of use, I have a great place to take photos of the tops of RR cars, but from the top it is hard to tell what the car actually is! So you may need to have some idea what it is and select images from a video. Also, they are sometimes moving a quite a clip and thus photography might be a bit blurry.
There is "rails-to-trails" pedestrian walkway over the U.P. (former C&NW) mainline that I have taken a few movies from... quite scarry to stand directly over the tracks with a pair (or more) of SD-70MACs coming right at my feet! First time I stood on the bridge my antonomic nervous system decided to take my body off the bridge... quite litteraly, I could NOT stand my gound! Second time it was all I could do to hang on to the handrail and try not to leap in the air over the engines and double-stack containers passing under me! I am getting better at standing still and may someday get a video without my screaming on the audio portion of it! Just got to remember to take earplugs next time. The bridge is right next to the river so the engines are usually throttling up to maintain momentum to get up out of the river valley and the exhaust noise is almost as loud as the horn blaring for the adjacent city street grade crossing.