Thank you, Paul, for helping to fill in yet another piece of the jigsaw, and for your kind comments.
I can now tweak the Sowerby and GMB RD databases on the Glass Queries Gallery with the definitive RD and Sowerby pattern number correlation.
Isaac Newton, the great mathematician, physicist and astronomer, said, "If I have seen farther, it is by standing on the shoulders of giants", and any glimmers of light that I can shine into the darker recesses of 19th century British glass design registrations are only possible with guidance based on the hard work and dedication of so many ground-breaking previous researchers (Thompson, Murray, Cottle, Slack, Lattimore, the Stewarts, the Thistlewoods, etc., etc.) and selfless assistance of you supportive GMB members.
Fred.