I may be wrong but I think they may be by Phil Robinson of 1980's fame, or certainly someone copying his wonderful style. Anyway, I've now completed the second of these units, by adding two extra companies and touching up some minor damage.
I still love [ perhaps too strong a word] Hinchliffe figures, and can't help collecting them whenever I see some well painted figures. My poorer efforts are tucked away at the rear of the unit. I just couldn't replicate the black lining and grey undercuts of the other figures.