The technique used here is zanfirico, also called filigrana a retorti or retortoli, rather than latticino, a term not used in Murano. It looks like a good maker, but it's difficult to pin down a precise maker as so many companies produced work like this. The snapped unground pontil is one clue. Another would be how the glass feels (sounds silly, I know, but it does make a difference). Is it hard and clean, or soft and soapy?
Nice piece, btw.