There is one lonely D&RGW drop bottom gondola;
The Stuhr drop bottom gondola. I have had no luck finding out is number, though the car may offer a clue
Into the late 1930's or so, the Rio Grande stenciled the cars number on the ends of the truck bolsters, here a "78?" is pretty clear
The other truck shows hints of what may be "787". Trucks could be and often were switched between cars, so they are not definitive proof of a car's number, but when they match they present a pretty strong case.
Next the boxcar and the 6600 series flatcar
Jason Midyette