Something you should watch out - common imperial russian counterfeit coins don't normally pop up until now and looks like it will pop up more often:
Weight stated is 19.2g versus 20.73g of an original. (a big slipoff obviously)
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...em=290110952969
With such surfaces, it shouldn't be too hard that it's a cast copy or some sort.