MemoryMoog: How to clean dirty contacts?

Hello synth experts,

I've had my lovely MemoryMoog for many years now, but it had been sitting untouched for quite a while. When I powered it up last week, I discover about 10 keys in the left keyboard region do not play sounds while the rest of the keys work fine. This leads me to believe I may need to clean the contacts (but I'm open to other suggestions).

Once the monstrosity is open, what should I do next? Has anyone tried to clean the contacts before? [Full disclosure, I have not opened the keyboard myself, but I had it opened and repaired by a pro several years ago.]

MemoryMoog