Hi Jeff, welcome to the board.
Anne has already found out a lot.
I think you can exclude Czechoslovakia as origin of your vase. They had their own pavillon at the 58 Expo, and the vase doesn't look like glass produced there in the 1950s.
(BTW, Czechoslovakia was never part of the Soviet Union).
Unfortunately, Russian midcentury glass is not very well documented; well, at least not in any language I can read

Kralik and Loetz went out of business well before 1958...
Michael