Anita, is it still bullicante when the bubble of glass is created by a means other than piercing the gather with spikes, either in a pineapple mould or on a flat bed of spikes on the marver? There was a discussion some time ago and how bubbles could be produced by introducing small peas of glass into the gather. When the pea melted, it left a bubble behind. Murano used this technique for some of the bigger bubbles and it looks as if if this ashtray might have used that technique as well. That said, it's definitely Murano and definitely bubbles. Anyone on Murano could have made it, though.
David