Dear friends,
I am happy that I can confirm that this piece had been designed and also cut by master hands of František Vízner.
Frantisek called it simply "cubes". He used the glass material from Mstišov glassworks, later when factory in Msišov had been closed he used glass from Karlovarské sklo. First cube made František in 1962 when he worked in Rudolfova hut as pressed glass designer.
There were cut machines in Rudlolfova hut just for finishing bottoms of pressed glass pieces, afternoons when workers left, František used their cut machines to make such things, just a side job, source of money. He had sold it in Prague, at Narodni street to art-craft shop. The usual price was about 600 Kcs for the piece, the medium salary in Czechoslovakia was about 1000 Kcs at that time.
Frantisek had told me that he had some conflicts with cutters in Rudolfova, becouse he usually destroyed their cut equipment, he told me that he was not very skilled cutter. He also mentioned, that when he sold in Prague two or three "cubes" he had felt himself rich like Rotchild, walked through Prague with nose up. :-)
I attached the picture made by Frantisek, we tried to sumarise and date all of pieces he made.
Jindrich