According to Roger Dodsworth's book 'British Glass Between the Wars' - he says of the single word backstamp ...... "Registered as Trade name 1927, User Claimed from 20 May 1924. Of the slightly later mark 'Made in - over Tudor - over England ....... he says simply 1930s. This second one gives rise to the joke Made in Tudor England

I don't recall seeing your mark before Keith, but I may simply have forgotten. Nice glass - small relief diamonds would you say?