Discussion about the Korg PolySix synthesizer

Just wanted everyone to know that I bought a polysix today from a guy 
I know.  I offered him $200 and he said "I'll just give it to you for 
$100".  I about shit myself!  A couple keys didn't work so I opened 
it and cleaned the contacts.  Works great now!  I also checked for 
battery leakage and it was fine.  He did say that he changed it about 
8 or 10 years ago.  Now I'm looking for a MIDI kit so I can hook it 
up to my Ensoniq ASR-10.

I got hooked on anolog after playing with a Korg MS2000 at my local 
music store.  This will be my next purchase. 

Are there any other upgrades to tweak the polysix besides MIDI?