With respect to Jindrich, I’m pretty sure Michelle's piece isn't a Zertova bowl, or even one influenced by her. As others have said, this is a very typical Murano design. Fratelli Toso, in particular, did many bowls and ashtrays with the folded over section and the roll into a tight little shell at the end of the fold. The use of the foil is typical of Murano at that time. This one is unusual for the having the foil round the circumference of the bowl and the charcoal colour in the centre. I don't think the signature will lead to the maker.
Here’s an ashtray with the shell effect.
I'd start by looking at Fratelli Toso and then AVeM.