Where do you live in Russia? Do you ever travel through Moscow? Can you get <<Iz Ruk V Ruki>> (the newspaper) where you live?
What are the names of those thick and thin circles in Russian? Gaika?
If you go through Moscow, you may want to visit the Avtorinok on the West side. It one exit north of Mozhaiskoye Shosse on the MKAD. There are lots of dealers and B/U parts there.
I ahve a mechanic friend who lives in the Otradnoye region who has his own Mercedes. I think it was a W123 body style - I don't remember as I drove only BMWs in Russia.
Other than that, keep asking around this forum, it is the best resource in either hemisphere.
81 300D 250K (sold)
79 240D 200k
83 Volvo Station Wagon (282k)