Hi,
"Barolac" as correctly Della said is not company but trade mark of special type of pressed glass production - always opalescent. It had been produced befor WWII in Czechoslovakia, later moulds had been used in Sklo Union factories. This is not "Barolac" piece but piece produced with ussage of same or simmilar mould. Colour does not correspond to Czechoslovakian production, as far as I know. Let we wait for Marcus' decision.
Jindrich