Bondo's 6X6 Scale/Crawler recovery truck

[TexasSP]

It's pretty cool what all is available to weather things with. The RR crowd has it down to a science. If that isn't good enough for you electroplating works real well too.

http://www.micromark.com/plating-and-etching.html

and some weathering products:

http://www.micromark.com/weathering.html