Discussion about the Korg PolySix synthesizer

I have a PolySix that is in great shape, except that the 6 synths are out of whack.  That is, 
you get a different sound each time you hit the same key.  I tried to make it louder a little 
while back, and ended up adjusting the wrong pots.  After downloading the PolySix service 
manual and trying out a few things, I'm stuck with a screwed-up synth.

I have an auto-ranging digital voltmeter and found a pretty good oscilliscope app 
(SignalScope) for the Mac.  From what I can tell, though, I'll need a real scope that I can 
connect to the circuits.  Is that correct, or can I just use the output from the 1/4 inch 
signal out jack?  Also, it appears I need a "dummy 56Kohm 2-pin connector"--what is 
that, exactly, and where is the KLM-376 2P plug?  I see a few plugs on that board but none 
with 2 pins.

I haven't done a lot of electronics work, beyond putting PCs together and a botched 
attempted to build a stomp-box, but I'm a reasonably smart guy and I love messing 
around with stuff.   Would I be getting in over my head to try to calibrate this PolySix?  
Would the cost of getting it repaired be less than the cost of a scope?

Thanks for any advice.

DGB