Hi,
This vase is Czech, I had one a while ago with a circular 'Made in Czecholsovakia' acid stamp. I'm sure the maker was eventually identified; I don't have my reference materials to hand, but I think it was Feigl & Morawetz, Libochovice. If you've got Marcus's Sklo Union book, have a look through the Libochovice before 1958 catalogue.