many thanks for your input Fred.

Not an easy one to resolve, made more difficult by the absence in the records of Rd. Nos. linked to factory patterns, and vice versa. Not realizing that the original decorator had applied the wrong pattern number had me more confused than you can imagine, but since that is now clarified then hopefully we can agree that Greg's bowl is Rd. No. 340003 which agrees with Sowerby's own catalogued pattern 1478.
I'd started out thinking this and then got lost somewhere.
I have Kew pix for all of the five Rd Nos. from 18.09.1879 - of which I've already posted a pic of 340003, and will post the others for reference purposes later this morning.
In the National Archives, the original images provided by Sowerby to the Board of Trade - for these five September Registrations - carry the following factory descriptions - and against which I have placed in italics Simon Cottle's own description and his interpretation of the factory pattern No., where he includes one:-
Rd. 340002 - basket -
basket (1442) 3 - bowl -
bowl 4 - sugar -
sugar basin (1478) 5 - square vase -
square vase 6 - handled jelly -
bon bon dish (1443)(this last item is a shallow dish with single looped handle - what we might now call a nappy).
A mystery why the last description differs so noticeably when the others agree - perhaps Cottle hadn't seen the Kew description?
But the real issue here is the possible confusion regarding Nos. 340003 and 4, and I have to say that I can't find an image of 340004 (the sugar) in the CD catalogue - I may have missed it so help needed please. You will see what it looks like when I post the Kew picture.
In his book, Simon Cottle links (visually) pattern 1478 to a picture of a (large looking) handled bowl - which appears to match Rd. 340003 - the same item as Greg's.
However, in his text Cottle links 1478 with his sugar basin, and links it to Rd. 340004.
Looking at the Kew images for both items, they would appear to differ in size substantially.
So we need to find a catalogue picture of 340004 - the sugar basin - but there does seem to be a possible query re Simon Cottle's linking of the bowl and sugar, with factory pattern Nos.