Vintage Synth Repair

I've got this olde yamaha cs01 which is functional but in a bad shape
- no case, just bare electronics. It's a wonder that this thing works
at all. I would like to make a new case for it and also seize the
opportunity to make some modifications on it but I need some advice on
what's possible to do and what not, so here's what I wanna do: 

- I want to replace the wave form selector with individual switches so
that I can mix multiple waveforms with each other (saw+tri+pulse and
such) 

- I also want to add another row of switches to individually select
waves to modulate the filter by osc.

- I want to replace the switch for the mod wheel with individual
switches for vibrato and filter modulation and add another one so I
can modulate vca as well and one to bypass LFO modulation.

- I would like to add ADSR controls for OSC and VCA and a switch for
each and VCF to bypass either of these.

- I want to add controls to shape my own waveforms (kinda like on the
Roland sh3a.

- a input for VCF and OSC would be cool, if that works at all (audio 2
OSC that is) and some patch points would be awesome so that I can do
stuff like syncing vcf to pwm and such.

- Also I need to get the LFO to modulate much deeper and faster/slower.

Lotsa plans, eh? Well let me know what can be done and some
examples/instructions for already accomplished mods would be veeery
helpful and time saving.