Hi Deb

Your vase is Rosice, pattern number 985, and came in 3 sizes: 20cm, 25cm and 30cm. Unfortunately, I don't know who the designer is.
(Have you got Marcus Newhall's
Sklo Union: Art Before Industry? If you haven't, I highly recommend it. It's a great reference for collectors interested in postwar Czech pressed glass, and includes a searchable database and catalogues.)