Discussion about the Korg PolySix synthesizer

Hi there,
I'm reparing a PolySix that I bought recently because no one did :-)
and I'm starting in the KLM-367A, there no signs of battery problems,
but a mice made the PolySix his W.C. witch means that I have to clean the board very well.
My questions is regarding what parts shall I replace?
I was thinking in replacing all 4000, also the resonator was broken
is the part listed as HWZT-6.00MD by Mouser a good one?

Thank you in advance for your help.

jorge