I have not knowingly seen a Jan beranek signature either Jindra. This is, as you surely agree, with Michael (Rocco), the signature of the Beranek family member Jindrich who emigrated to Austria to make glass for most of his career. This is why many of his pieces resemble 1950's Skrdlovice, because he made (and designed) such pieces at Skrdlovice for a short time in the mid 1950's.
Robert (bOBA)