Here is the main producer and distributor that sells to Bigtank.de and Mark-1 tank. They also supply a US distributor and a japanese one. You can order directly from here though. They are located in Moscow but the tanks are molded in Volgograd (formerly Stalingrad).

http://www.interdacom.ru/~tanks/

Yes i am military. Not for too much longer though my time is coming up to get out of the armed forces.