I'm dim on this type of thing, but to my eyes it lacks the quality and breadth of cutting style you'd expect from VSL - much of which has more of a deco or modernist cutting pattern, and not a simple naturalistic style like Christine's, which doesn't appear to be style of cutting from the '20's or '30's. I'd still plump for Czech., perhaps German.
If you look at examples of Novy Bor (Karel Wunsch) cut bowls in Mark Hill's book - which I know are different colours, lack Uranium and are abstract cutting styles - but there is some similarity of modern coloured casing/cut to clear, which made me think of Czech. Could be well wrong of course.