These were done by a few people for different companies. The design looks like Livio Seguso for Seguso AV, but I haven't seen a sommerso one done for them. The sommerso looks like the type done for Cenedese and Salviati during the time. I don't know, but I think that Livio might tie these companies together around 1970. Many of their designs were similar around this time. Anyway... I think you're right that it may be Livio, but I don't know for which company.