Roland MPU-101 part question

[DrTempus]

I just picked up an MPU-101 cheap ($59), but the

mono/2voice/3voice/4voice/special switch bank
is badly corroded and rusted. so much so that
I had to replace 3 dissintagrated diodes.

Does anyone have a service manual handy to let me know
the part number for this Alps switch bank?

or if you happen to have a spare part, I'm looking to buy.

much thanks in advance.

It's amazing how well Roland gear rusts. ;-|, I
suppose somebody must have spilled something on it.

-Allen
 www.darkaether.net