Yeah they wanted to turn the Polish religion into a Russian one which meant Church Slavonic as a lturgical language, it was not successful and I suspect only a few, if any, masses were said in Church Slavonic - which is not that radical as far as liturgics are concerned since the Tridentine mass (the so called "gothic mass") in Croatia, as I am sure you know Father, was said in Church Slavonic (btw this is all according to the Polish history section of a John Paul II biograhy I have).
I think you mean the
Glagolitic [
newadvent.org] Missal... Which, I have been trying to learn more about for years.