thanks for the feedback from Mel and Christine. I'd not been aware of seeing any more than these two, but quite small, so could be missed easily I suppose - and certainly very rough and ready - but with a sort of rustic charm.
Jules Lang & Co. and the subsequent change (around 1904 perhaps??) to Jules Lang & Son, seems to present a long and complex history - they purchased moulds from several U.K. factories - bought glass from Continental and U.K. firms and seem also to have made their own in France. If you use the Board's search there seems to have been a fair amount of interesting chit-chat in past years.
Regret I don't have accurate information on their history, so can't give reliable chapter and verse, but this would make a good meaty subject for anyone who has the time and interest to research.
Pressed glass isn't my thing really, but I collect drinking glasses, and like old things - and with the potential of this being a genuine antique,
think they make interesting pieces of social history, so worth keeping.
I'll see if I can find some more.