Way to drop some knowledge Chappy! I love the Testors thinner, and I pick up a bottle of it every time I find it. BridgeTown usually it if I remember correctly.
I also have great success gloss/oil wash technique, I used it for all of the black lining on my Tau. I can really see where it would work for this as well.
I love the idea of the workshop, I'd be there!