Vintage Synth Repair

I'm curious if anyone has ever thought about modding a Korg Mono/Poly with CV jacks for it's various parameters? 

I'd love to be able to route the white noise to different locations. I'd also love to have CV/Gate Jacks for each oscillator.

How could I safely find the points in the circuit to put a jack?

Has anybody done this on other synths?


Thanks,
Johnny