Thanks for the encouragement on the Semo guys. This is the first AFV I've tackled in 20 years, and I was never an AFV builder back then!
The wash was a mix of Windsor & Newton Black & Burnt Umber water colour applied liberally with a brush, and allowed to harden before being wiped off with a damp Q tip. In typical wingy thingy fashion I AB'd the entire vehicle in Future, not sure that the armour guys do that prior to a wash, but it worked fine for me.
The tracks are all painted as well now, just a base coat of Tyre Black, followed by a light dusting of Rust, and then a dry brushing with Steel.
I'm hoping to have it finished this weekend, with pictures to follow.
By the way, what topic are we supposed to be on? Same faces, different GB, just not sure which any more.
Karl