For comparison, here are some images of a blue pot I sold some time ago. This was the same shape as the one in Barbara's post - I know as it was that thread which initially led me to attribute the pot to Walsh Walsh. Having seen this labelled example & heard Ivo's opinion, I now think that attribution was likely to have been incorrect, though I need to get a better look at the one I've just bought before I can be sure.....
It's also got me questioning other supposedly Vesta Venetian pieces, for example the orange pieces discussed in the posts above. In fact, I've just acquired another item in this orange, a jug with the same opalescence and 18 rib pattern - I'll post more pics when I get the chance.
Steven