I forgot to say that this was done by using aerosol to lay down some basic rust colours all over, then brushed green over most of the body ( for instance not at the bottom, where rust was creeping up) and then sponged dark rust followed by a mid rust over all rust areas and roof. Everywhere had talc applied generously whilst still wet, waited a few minutes a brushed off again.
By this time most of the green had disappeared, so green was reapplied selectively into grooves quite sparingly, again with talc following.
After thorough brushing off, a (quite heavy) black wash was brushed over the whole thing to tie it all together, which looked good wet, awful half dry, and very nice completely dried.....