And while we're bringing up this backlit buttons thread, I would like to repeat an idea I saw in another thread:

One of the feelings I got was that casting the back bits (the parts that fit onto the buttons and knob shaft) is the hard part.

You could cast just the front faces of the buttons and knob in a translucent material. The back portions could be cut-off bits of the generic farnell button caps and an extra standard knob, glued to the translucent cast pieces.

I'm itching for backlit buttons.