I have just received from a member a nice set of 7 Marx tinplate cars. These include a hopper and gondola.
What do you guys put in your empty transport cars, that keeps up the appearance of tinplate? Real gravel, coal, or sand, etc. may, I think, detract from the classic tinplate look.
It depends on the theme of the layout. On my Christmas layout, one gondola will have a load of small bottle brush trees, wrapped and dusted with snow for delivery to the local Christmas tree stand. Others will have sweets and small wrapped presents for my granddaughter. Making up loads is where you can have a lot of fun.
For a regular tinplate layout, how about a load of erector set parts? Pieces of old junker Tootietoy or Dinky cars or scraps of old tin lithographed toys? If you go to a train show, you can find lots of bits of junk under the tables. Or raid your parts bin. I have lots of lanterns form prewar switches, old (train car) trucks, Gondolas carried a lot of scrap. Any sort of colorful Stuff could go in the hopper. Fish aquarium stones. Beads. Polished stones sold for flower arrangements, etc.