I've not got a clue!
It does look a little like IoWSG Seaward, but the stopper is wrong. It also looks a little like Allister Malcolm's "Ripple" pattern, but to tell which this may be, or not, I'd need to see it "in vitro". Seaward and Ripple are quite different, but from a picture, I'm stumped!
Is there any optical texture in the glass? Allister Malcolm's Ripple has hexagon shapes in the glass.