I run mine empty. Richard Hendrickson used to put something inside as a view block. I forget exactly what, something like painted packing peanuts, to give an irregular shape if you happened to get them where you could see through the slats. Putting individual figures inside would be extremely expensive. 25 cows would not break you, but 300 sheep would!
Yes, he did use packing peanuts, painted gray. I have one of his stock cars so loaded. But I must admit, you have to really look carefully to see anything inside. Stock car slats aren’t far apart, and with a double-deck car, pretty dark inside.
