Many thanks for the replies. I was hoping for some suggestions closer to home. I like to visit a foundry to discuss details as to where runners and risers are positioned, type of sand used and so on.
I've heard good things about Manor Foundry, too far away though, likewise Hadleigh. As for Owlcastings, they need to get their website sorted, I lost patience with it!
I've considered buying melting and molding equipment but no. Time and space are at a premium, it takes time to develop the technique to produce castings of the required quality. As for melting down scrap aluminium, I want to know what I'm working with. Sometimes I have the castings heat treated.
As for multiple patterns, more work. At the moment its a small batch infrequently made. That may change in the future then multiple patterns may well be viable, preferably metal for durability.
John