Universities would be a place worth looking at if you have one with an engineering department around you, many seem to forget universities do a lot more than teaching and research. Hackerspaces if there are any around you (
http://hackerspaces.org/wiki/United_Kingdom ) might have one or one of their members might have one. Hackerspaces are probably the better place to find such things but there are also 3d printer hire/share lists.
https://www.3dhubs.com/3dprint is a reasonable start for one. Most of the ones around me seem to favour PLA (not the worst plastic but I would prefer ABS) but you might get lucky.
Equally if there are still any machinist/engineering firms around you then they might be able to fab something, that is a pretty annoying shape for general fabrication -- the base shape is OK but the pegs... those would be annoying to mill out of a larger block.
http://www.shapeways.com/support/shipping (the most popular/well known online 3d printing company) do ship to the UK for a reasonable rate. Their main competitors in
http://www.sculpteo.com/en/ and
http://3dlt.com/print-now I have not used in the UK.
Not sure what size that is offhand but it might be larger than some printers can handle in one sitting so be aware of that.