attractive creamer Roy, and unusual handle design - don't recall seeing anything similar before.
The majority of Board of Trade images submitted for Registration purposes were to protect a shape rather than decoration, and that is certainly the case with Sowerby Registrations from 11th March 1881, and I have copies of all eleven Board of Trade drawings from Kew. However, when a comparison is attempted in order to link this creamer with one of the Kew images from Rds. 362734 - 362744, it becomes apparent that contrary to usual practice the connection in this instance is one of decoration only, and not shape, and since Board of Trade images don't usually show the decoration, then answers can be elusive.
Fred has shown the connection between this creamer and Sowerby's pattern 1561 sugar, by means of decorative pattern only, leaving unresolved the matter of relating both pieces to a Board of Trade Rd. No.
I hadn't previously been aware of this problem but perhaps it's more common that might be thought.
There wasn't a design submitted for a creamer on that date, neither do any of these eleven National Archive images show any decoration, so to assume Board of Trade Registration protection for a creamer that doesn't relate to the image/shape on which the Registration was based, might seem a weak/tenuous link, and substantiating a connection between the creamer and the Board of Trade Registered shape would seem on the face of it impossible.
It might be thought that Sowerby were misusing the Board of Trade rules, or at least stretching them to suit their own purposes - plus of course it makes life difficult for those of us who, 135 years later, try to link what appear to be unrelated items.
The fact that we can solve such problems is due in no small part to the Thistlewood's publication of factory pattern details, plus of course other quality publications on pressed glass.
As suggested by Fred, it's necessary to look at the Thistlewood CD (VOLUME THREE) - Pattern Book XI - where this horizontal herringbone decoration can be seen on both a sugar and creamer under factory pattern No. 1561.
Using the shape of Sowerby's 1561 sugar, this is compared with the National Archive images from 11th March 1881, and my opinion is that it corresponds to Kew image for Rd. 362739 (picture attached), which carries Sowerby's own description of 'New Shape Sugar'.
Having made this connection, it's then obvious that the herringbone pattern of this sugar matches Roy's creamer - QED, I hope.
Please comment if people consider that Rd. 362739 doesn't compare favourably with the shape of sugar 1561 in Pattern Book XI.