Here is a shot of RS36 #5017 from July 28, 1983 leading a track maintenance train. It is somewhere near Sanataria Springs, NY. I knew I had this slide somewhere in my collection and I looked forever for it, finally finding it in the wrong place. I had referenced it earlier on my blog.
I don't think anyone offers an HO scale model of the ballast cleaning equipment, but it sure would make for a neat train. Note that everything in the train is yellow including the former passenger car, whereas most D&H maintenance equipment during this time period was solid blue. Maybe Colonie was still out of blue paint?