Brought it indoors, washed it, and went over with a magnifier but no marks at all. 41cm/16" diameter. The ones I have seen on the internet all give Pauly & C as the attribution, but no references given, and one of the four had "?Pauly".
CMOG have 28 pieces attributed to Pauly on their website, but none of these bowls. Unfortunately, I don't have any specialist Italian glass books to check.
Interesting that the only blue one I've found was the one in the listing above. Given that cardinals' hats were red, perhaps they didn't make many in blue. Surprised it didn't sell at $50, if it is a rare Pauly piece - especially as the ruby ones I found were listed at £1500 and £1250, sold at £385, and the last one was price on application.
I will continue the search.