I have a catalogue from this St Denis glassworks and note it (Ivo, Glass A-Z) was formerly Legras. They did dome of those moulded vases with mostly natural motif's; fish, birds, leafs etc. and was wondering id this was the type of piece designed by Heiligenstein?
All I found Googling was that the company tried unsuccessfully to takeover Compagnie de Saint-Gobain in 68 and failing that changed its business and became Danone.