Vintage Synth Repair

Hi all.

I've taken on the repair of a Korg Poly 800 Mk1, but I think it might
be a bit of a challenge!

First and most obvious problem is that a set of batteries has leaked
into it at some time in the past. There's corrosion on the PCB, some
of the IC pins and some of the keyboard metalwork. Does anyone have
any suggestions for how to go about cleaning it up, or will the damage
be too far gone?

Supposing I get it to work, the next problem is that a previous owner
has been a smoker - the keys are stained and it stinks of smoke. Again,
any recommendations for cleaning it up?
 
Cheers

Mark