Hi, thought this might be of interest. It is optic ribbed, 86mm tall, and acid stamped with ‘REG DESIGN 830234 MADE IN BELGIUM’. I’ve not managed to find another on the internet.
The reg. design number would be the British one wouldn’t it? I’ve not got the blue book but have looked on great-glass.co.uk where there is a list of the design numbers but nothing for this number. The list has 830233 registered on 4 August 1938 so assume this design was registered close to that date? Does anyone know the maker? Thanks.