Sorry, I’ve been neglecting this thread – so here’s a short update on the BA-6. With some fitting and clamping, I managed to get the top shell cemented in place, and then masked it for airbrushing.
I then began to experiment on my paint mule with a brown basecoat, before deciding to stick with black. Then I messed around with various green shades, using the Vallejo Russian 4BO Green as the base, until I was happy with it. Very happy to have the paint mule at hand – it’s really helping me try things without fear of wrecking my main project.
There’s lots of ambiguity in the world of Soviet armor color tones, so I’ve decided that the main thing is that it has to look right to me. I really wanted to hit the green that looks “Russian” enough to be distinctive, even if it’s only “Russian green” in the eyes of modelers.
Anyhow, after the basecoat was on, I did some highlighting and mottling by switching to my 0.3mm airbrush adding small amounts of lighter green shades to my base color.
It’s now got a varnish coat that’s curing, and I’ll soon be on to chipping.
Meanwhile, I’m working on bending and building these photoetch tracks. I’m still not sure if I’ll mount them on the wheels or stowed on the fenders, but they are so tedious I have lots of time to decide. 
EDIT: I just realized that if I put tracks on this thing… it might pull it out of the “cars and trucks” category!! 