Gus and Genetk44-thanks for the replies and compliments.For the weathering I use basically the same technique that I use on eveything.I use black craft paint (Delta Ceracoat).I dilute it with water and brush it on.I then wipe it off with a paper towel,leaving on as much as I want to get the look I'm after.You can always put on more.If the wash is too thin,add more paint.Once the black is dry,I go back and dry brush rust,dirt,etc.The nice part is if I don't like it I take an old tooth brush and run it under warm water,wash it off and start again. For the trucks,I fitst painted them with PollyS rail tie brown. I removed the wheels and did the insides of them as well.On the trucks I did only what will be seem. When the brown is dry I make a wash of PollyS rust and go bck over the truck.When dry I replace the wheels and spray the whole thing with dull coat.
As far as a load goes,one of the railroads customers uses steel to make 55 gal. drums so I figures rolls of steel and perhaps some wood reels of cable.
I hope my weathering description helps.Bob