Thanks folks for the kind words!
As far as the weathering techniques I wrote a couple of articles on how to weather coal hoppers. The articles on weathering the wheels, weathering the trucks, and making home made coal loads have been published. They can be found at the RailroadForum Magazine at:
http://www.railroadforum.com/magazine/contents.html . The truck weathering is covered in Issue 4. You will have to select the archive and choose the Wheel Weathering from Issue 3.
I am currently working on the last article for the series. It will cover weathering the car body. I am hoping to have it complete for Issue 5 will be coming out later this summer.
When I get back from vacation this weekend I will talk about the track weathering. It was basically done with a brush. Since I will be doing more shortly I will be taking photos to document it.