I was really happy to find this vase the other day here in Sydney, Australia.
At Jindřich Pařík's site he has a copy of an article by Šárka Kolářová on František Zemeks Hüttenglas in the Glasrevue 1957/3.
https://picasaweb.google.com/104509467784289017506/Glasrevue19573?authkey=Gv1sRgCOznh9bYg4ncQg#5438153564383438946The description is in German "Hüttenfertige Vase - Erzeugnis Nr 52031/19cm.
My vase is just a little bit higher at 21.5 cm. The opening on the lip is narrower too!
But the colours (amber, pink,blue and green) are so restrained.
All four of the 'tadpoles' glow lightly under black light.
Can I ask a question about the model number?
Erzeugnis Nr 52031 - does that mean a date of 1953? or is this a design of 1957 (when the article was written)?