I've been trying to locate 4 more coins of this series to complete it. Couple of these should be easy but I've been lazy. The smaller denomination of 1921 coins are difficult for some reason - probably low mintage from the start. 1922 ruble was hard to obtain in a reasonable price. I'm definitely not considering the 1923 chervonets... http://gxseries.com/dump/russia_1921_23_rsfsr1_small.jpg http://gxseries.com/dump/russia_1921_23_rsfsr2_small.jpg I really like the toned coins. Show off your awesome RSFSR coins!
I won't buy one of the 1923 Chervonetz coins because the prices are inflated, and the 1925 is impossible so I settled for the 1979 version that was sold through Mezhnumizmatika: Like the original, nobody in the USSR save a few apparatchiki in Mezhnumizmatika and Goznak ever saw these - they were intended for the export market only. For a long time until a few years ago these traded right at spot - now they are recognized as scarce in their own right. I do have the 1923 dated 15 and 20 Kopek coins, but not the 10 kopeks so far.