By the way, Paul, your photo of the design representation for RD 345042 closely matches the shape of Sowerby pattern 1510 (which appears on page 10 of their pattern book IX, 1882). It is not cross-referenced as such in Cottle.
I’ve never seen an example, and I don’t have any photo references of an actual piece, so I wonder if anyone does have a photo of a piece in pattern 1510 to show, please?
Fred.