I just received my Marstar Chinese version. The price from Marstar, with taxes and shipping, is the same price as Tradeex with taxes and "free" shipping. Mine is new, all numbers match, and the deal included 400 more rounds of 7.62mm.
There might be many good reasons to buy the Russian version, from Tradeex, but price isn't one of those reasons.
I have the stock cleaned now, and wiped down with a dark stain. Just left the stain on very briefly, so it makes the entire stock a uniform colour, and then wiped it off with a clean cloth. I'm pleased with it.
After handling the bare stock, and doing some sanding, I swear it is made of teak. Any opinions on this?