Here's the stage breakdown that I used Chris.
1. frame
2. cab
3. rear axle
4. front axle
5. winch assembly
There were a couple of other small bits and pieces that I left off to just to ease the painting. Things like the wiffle tree, acetalene tanks, etc.
Basically the underside is O.D. except for the exhaust system which would have burnt the paint off of it anyway.
Reference sites:
www.ferreamole.it/images/Dragon/m25_dw_01.htm
http://www.amps-armor.org/Preservation/DW-Pics.asp?F=01
http://afvinteriors.hobbyvista.com/dragwag/dragwag1.html
That should keep you going for a bit.
Happy Modelling and God Bless
Robert