Shapeways can 3D print aluminum (and several other metals). If you can model it you can have them produce them one-at-a-time, and list the end product in a shapeways store so people who want them can buy directly when they need it. If you set it up with no profit margin, they don't charge any fees for the store listing... it just sits there forever until somebody orders. What's great about this solution is nobody has to front money for an inventory that could take a very long time to sell/distribute.

If you want to see an example of a shapeways store search for kahrparts on their site to find mine. I have some pics up there of Firepower outlanes viewed through a microscope so you can see the quality of their prints (I think the microscope shot is of their "metallic plastic" if I remember correctly)

-Rob
-visit http://www.kahr.us to get my daughterboard that helps fix WPC pinball resets or for Williams system 3-7 sound board potentiometer solutions