[sdiy] KorgMS20 mods? help?

[peter edwards]

I see that there's been a fair amount of discussion in this group  
concerning the Korg MS20 (great rebuild by Julian btw!! http:// 
www.port23.co.uk/ms20/) so I hope this isn't a tired topic......
I've owned an MS20 for about 7 years now and haven't had a single  
problem. What a great synth! Now that I've really gotten to know  
every bit of this machine, I'd like to take it further and expand  
it's functionality. I love this synth and would hate to fry it so I'm  
taking the cautious approach and looking to those with more  
experience than I for some pointers.
I'm interested in adding some controls like a pulse width CV input as  
well as further patching options like ring mod inputs and an EXT in  
mixer. I would also love to add some modules like one or two more  
LFOs and CV mixers.  Has anyone looked into modularizing?? VCO  
outputs, VCF ins and outs. I suspect that it would be more trouble  
than it's worth.
Anyone out there with some experience who could give me some advice,  
schematics, links, etc...
I'm not a pro, but I've got some experience and I'm real good at  
following directions.
Thanks!!