If you want to call Matrix, that would be great. If nothing else, you could learn a little more about the process, the options, the quantity limits and unit costs, materials costs, and setup costs. That RIM method sounds good.

And Smooth-On sounds like a good resource for finding a caster. They are actually under an hour from my house, but since they don't do casting, that's not too much of a help.

If you get any casters, post them here so nobody else calls them also. Actually, it might be kind of funny if they got multiple requests for small run of odd buttons... but it'd confuse them.