Armo have released a kit of the Russian armoured car/self-propelled gun based on the Mannesmann-MULAG. The blurb says it was used by Tsarist Russian forces.
Some information on the donor vehicle here: http://de.wikipedia.org/wiki/Mannesmann-MULAG
Tracks and Troops have it for sale: http://tracks-n-troops.eu/shop/index.php?main_page=product_info&cPath=14_1&products_id=11908
And, obviously, Jadar have it: http://www.jadarhobby.pl/armo-72151-mannesmannmulag-armored-car-172-p-33062.html
"We're forgetting-machines. Men are things that think a little but chiefly forget. That's what we are." - Henri Barbusse, "Under Fire" (1916).
That's very nice. While waiting these odd Russian inventions, I have had to built some from scratch...