I'd check out with someone in the
http://www.cnczone.com forums. Chances are there might be someone close to you that can give you a quote and check the files. If those reliefs can be modified to slot in rather than being machined from solid material it might be possible to build the entire thing with a simple CNC router. You might even make them so that they will hold the two lower sections together once snapped in. Glue the lot with epoxy, sand it and paint it black and it will look as a solid piece anyway