disappointing to see that a member of The Society of Fine Art Auctioneers should be that slip-shod over a very basic matter as the value of looking up a Rd. No., and thus turning down a golden opportunity of being able to say so much more about an item.
Not everyone has the Blue Book, but just a couple of clicks on the screen will bring up the Kew data from which it's obvious that this is nowhere near C19 - and there are other internet sources that will show this is a C20 Registration - not remotely a difficult conclusion to reach.
So much for the accreditation value of SOFAA.
I see that there were two Nos. registered on that date Steven - does this indicate two shapes/patterns perhaps?
Otis - hope you don't mind - am attaching three pix which show some other non-opalescent shapes in this pattern - yours is a nice piece by the way, but as you'll see, you have a long way to go to complete the set