Discussion about the Korg PolySix synthesizer

Hi -

Sorry, a newbie question. I just picked up a Polysix that needs 
minor repairs. Fortunately the battery is fine, at the moment. 

I'd prefer to replace it with a rechargeable one similar to the 
original to avoid the extra modifications that seem to be necessary 
when using a lithium battery. (I know that may still leak one day, 
but not anytime soon.) I thought I saw the part described once, but 
now I can't find the reference. Any advice...?

I also need to replace one of the patch selection buttons, which is 
functional but worryingly loose. And after reviewing past comments 
I'm still not 100% sure whether the pitch bend wheel should be 
sprung or not (though I'm guessing not)...

Thanks for any comments,

Ben