Vintage Synth Repair

Hi,
 
Does anyone on the list service or know about Lowrey organs?  I have a rare
three manual GX-361 / G-7000 that needs some repairs.  The lower two
keyboards and pedals work fine.  The upper keyboard, which is a solo section
doesn't work properly.  Just about all the solo voices have a fuzzy / buzzy
sound to them and don't play in tune -- random pitches, not following the
keyboard notes.
 
To keep this on topic, said solo section sounds are polyphonic analog
synthesis generated (i.e. no samples)
 
Thanks