Dixon's has a great selection of castings, however, they do not do their own casting. The shop has a well organized system of cubby holes marked with different schools for buttplates and guards, often in iron, brass and sometimes German silver. They do not have a catalog, but if you call them up, you can probably get what you want. Greg and Chuck are very knowledgable. Better yet, put you list together, and go in person. I live 4 1/2 hrs away, and have made the trip in the winter just to shop.
Tom