Would also like to see the MK5 . As to it not being viable commercially strelets has covered some pretty obscure conflicts already . The Russo Turkish war with I think 12 sets springs to mind .2 sets for the Chaco war seems doable especially as they will be the only ones in the marketplace
The South American wars of independence might also be interesting. Would love a set of Bolivian line infantry in red! I don't think we'll ever see them, though as many other sets from similar time periods can be pressed into service here.