Caught one! Still trying to catch the other two.
This small fish dish is from 1956. Made by Hornsea Pottery, it's decorated with a series of dots and trails of liquid slip in black, pale turquoise and pale yellow. It's from a set of three. There's also one with a black background and one with a blue background. I'm still trying to find the other two.
As well as the fish dishes, Hornsea made a whole range of these small slip-decorated dishes in the mid to late 1950s. They come in a variety of shapes: square, triangular, oval, oblong, some are decorated with a butterfly. I'm not as keen on the black background dishes, I think I prefer those with the pastel coloured backgrounds.
For anyone who would like to see pottery like this in the 'flesh' and is in the area, there's a huge range of Hornsea Pottery on show at the Hornsea Museum