Nice idea, but you are likely to have problems with porosity - it is not like to polish up as good. Would really have to look at investment casting or dye casting, and they are a little more expensive. Or you find someone who will let you use their CNC milling maching. Even that could get a bit trickey - is only good for very small runs. Got a 3D CAD model of the faceplate Rob??

(list 6284, Mk1 S/N 00299 4GB blue [for sale]. Mk2 S/N 080000094 6GB blue)