Kev, you have a remarkable ability to pick on utility glass that for the most part will have been made anonymously, in this case, for a lighting company. Most of whom outsourced their glass to whoever offered the best deal. Printing or transfer decorating could have been done at the glassworks, the lighting company or a separate glass finishing company. I have many lighting catalogues from this era and there are mostly no clues to who made the glass. As to identifying the lighting company... there were/are a LOT of them. I will put all mine online in due course but I don't have anything like comprehensive ranges of catalogues.