Hum... I honestly think that, regular coins that were minted in the same year as the commemorative ruble coins are pretty difficult to find, like 1834, 1839, 1841, 1859, 1883, 1898(exception), 1912, 1913, 1914...

(hopefully I didn't miss any years out)
Sekine's link has *SOME* of them, but not all... which could mean that it can be proved to be quite difficult.
http://park3.wakwak.com/~sim1351/index.html