Hey folks, here are a couple more pics. 
For the one of the back plate, this is 1/8 steel scrap that I had. I like the patina.
From left to right you have

• USB for MIDI / power supply
• 1/4 MONO line-level audio out
• Octave down
• Octave up
• Joystick. vertical axis makes the controller louder / softer.  Horizontal controller bends pitches
• Four Red control buttons. (well 3 because the bottom one already broke.  No more cheap switches for me!) They are:  
  • cheap-ass broken button
  • unassigned
  • Change pitch bend between entire instrument mode or last note played mode
  • change wave form
• Two LEDs that initially showed which of the 5 octaves was selected, from one (bottom blinks twice) , 2 (bottom blinks once), 3 (no lights), 4 (top blinks once) and 5 (top blinks twice).  I disconnected them because the blinking was distracting. 

There is also a close up of the keys, where you can see the round Cherry MX key caps I am using for the buttons.  There is not really a pattern to what letters go to what switches other then the C-G  in the middle. The black keys are just white keys with sharpie.

You can see how tight I am for space on the back.  Im leaning towards making this model MIDI only and building a second prototype with a little more room.