Little late to comment....
I saw you say the plastic bedrolls did not conform well to the model. I would really recommend to try using kneadatite (aka green stuff). It's a 2 part epoxy and can be molded into great looking bags/tarps with creaseas. Use water to prevent it from sticking, and use a toothpick/xacto knife for creases. Mold it to shape of model where you're placing it, then brush paint the roll. Weather it up with pigments/drybrush and its good to go.
Also great work on the tracks, they seem very nicely weathered. It's subtle but looks very realistic!
Kien