I have maintained probably not Czech for a long time. I bought one of these in the UK once. I think they are circa 1950. Where bought, if given a large enough sample, can be indicative. This vase has proven elusive for a while! Pretty good quality, suggesting an established company. Never seen another colour though, with the coin sized polished pontil rod mark.... building up the colours available can help a bit too, with factory indication.... Interesting piece.
Robert