24 cm/9.5 inches. Here's the requested base shot. I'm certain it is not Polish or Chinese. It's genuine Murano and most likely from the 1950s or 1960s, although it's true they've been doing these sorts of pieces pretty much constantly from the 1950s to the present. My fear is that there's no way to definitively prove it's by A. Toso, Barovier, Seguso (etc. etc.). Not signed, so I'm assuming it cannot be Venini.
Charles.