quite a lot has been done, It has become quite the project, which i thought was worthwhile making in to a proper useable prototype in a modular synthesizer.
I have made a new board with switches and a MAX7221 LED driver to display the wavetable and bank numbers, as well as some indicator LEDs
The MAX chip only uses 3 lines, and the switch multiplexer uses the same counter lines from the pot multiplexors, and 3 more digital inputs.
2 of the switches on the switch panel are grayhill hexadecimal output 16 way machanical switches, they are very nice but the price is :o (lucky i found some on ebay!) that way i can select the wavetables and output a proper number to the MAX chip and see what the hell is going on! When i was using a pot to select the wavetable sometimes it would be halfway between 2 values and glitch all over the place as it switched between them.
(and i can use this same board for an arduino based sequencer or drum machine as well, so i made a few)
boards

populated and added to the monster arduino project

New panel properly drilled, but with no labels. the labels are photoshopped on(except those stickers lol)
sorry big pic

back. mostly wired

The 3 unused knobs are for the analog mod inputs which are not implemented yet, and for another LFO control which i haven't finished (i put the knob on once its working!)
I did do some work on the MIDIVOX version, and it is making noise, but i have to mess about with the code because the serial DAC is hogging too much processor time.