I don't think Italian is likely, but thanks very much indeed.
I've been discussing this with my wee brother, who suggests Czech as a possibility, and I think that might be the direction to go with it.
It's the combination of the '30s style optic ribbing, with the much more modern, perhaps '60s style, stopper which has led us there. The Czechs were incredibly advanced in glass design compared to this side of the Iron Curtain, producing the sorts of things we found revolutionary in the '70s way back in the '50s.
Perhaps they would be the ones who would use this unusual combination?