sorry to be a little useless on this as I wasn't really photographing them.
What I was photographing was the rest of the cabinet contents -which, checking back more carefully now, contained Theresenthal and Steigerwald glasses. This suggests actually my earlier comment was wrong. Passau seems to think they are German not Bohemian. (a bit of a weakness for Passau in my belief)
Now I know Steigerwald had their own version of sort of peacock trail, but that is very different and one cabinet further on. All I can be sure of is where they were, they are definitely not being classified as British!