Hi!
I just stumbled over the Bliptronic synth on the net: http://www.thinkgeek.com/electronics/musical-instruments/c4e1/
What makes it really interesting is that a guy posted the full pinout of the PCB. It seems by ordering and gutting a bliptronic you get a pre-made BLM and aluminium enclosure for just 50$.
I think from the description here that it would be possible to re-use the enclosure and blm for your own midibox projects… in fact, this guy even sells arduino-hack-kits for converting the bliptronic to an arduinome.
I think if the BLM pinout, voltage etc is compatible to mios (is it?), this could be interesting.
edit: found some more details, including a circuit diagram.