Very nice! And your rust work inspires me, I'd just decided to to a unit with poorly maintained battle salvage, so hints please!
Thanks!
My method was:
Prime with rust color surface primer (airbrush)
Spray cheap hairspray (not too heavy)
Let dry
Airbrush base coat and highlights (thin coats until coverage)
Wet surface and allow water to saturate down until hairspray layer, then use toothpick and brush to chip
Gloss varnish
A variety of dark grey, black and rust oil washes and streaks (using white spirits to make streaks and control where it goes)
Gloss varnish
Decals
Matte varnish
Light drybrush
Additional washes where needed for more contrast.
Hope that helps, please let me know if you have any other questions!