The paint I used on the Tamiya JS3 Stalin was a brand called "Model Maker Z" Russian Green. I purchased the paint about two years ago at a contest in Virginia. I searched the web today and could not find any on-line hobby stores that carry the product. They were a very small outfit and may be out of the business now. Their paint was very good with good color matches. They have/had their own thinner but I liked to thin it with MM acrylic thinner. I have now shifted to AK, Vallejo Air, or Chris Wauchops Tamiya color mix for late war panzers. In the Missing Links article below you can see the Tamiya mix Chris Wauchop uses. I think it looks real good.
http://www.missing-lynx.com/gallery/german/pantherglatecw_1.html