Max,
this piece is modification of Libochovice 3032 - see Marcus Sklo Union database. After pressing when piece was still plastic glassmaster has "opened" the shape with pucellas. The designer is for the moment unknown to me.
(btw. take a look at 13066 in Sklo Union database, here you will se example of "closed" shape - after pressing post forming. It was game of glassmasters, designer had not influence to this creativity.)
Jindrich