i do not know of any castings company out your way, but these people are just a mile or so from the other side of my village , bloody ace they are!! always been so helpful!! link=
http://www.dureycastings.co.uk/you can see the full catalogue on screen , request a catalogue all sorts matey, hope it helps, they could also put you in touch with a supplier near you!! and at the last count, they supply most of the UK's councils!!
go on!! give 'em a whizz!!