Thank you Nic. I think that was my point...
There are surely exceptions (and maybe not too few considering the long tradition of glassmaking in Venice), but bases like the ones on the pieces in question don't seemt to be the rule on Murano pieces, high or low end.
Funny that no one except Sue and me seems to be familiar with these bubbly pieces.
I have seen probably more than a dozen through the last years, on fleamarkets and online, both vases and ashtrays.
(On ebay Germany they are usually offered as Löffelhardt for Zwiesel)
They come in a variety colours, including green, blue and bright yellow, and always have the flat roughly ground base and the metallic iridescence.
I first heard of the Romanian attribution here on the GMB, but it seemed very convincing.
Michael