I specialize in Sequential Circuits synthesizers, and have done some good work on others (Oberheim, ARP, etc).  Average turn-around time is 5 days.  Unless otherwise noted, repairs are warranted for one year (this covers labor and non-custom parts).

Some other repair persons you may find useful:

I don't provide service for electromechanical keyboards such as Hohner, Rhodes, Farfisa, etc.  For these repairs go to Matt Cunitz at Vintage Keyboard Repair.  510-527-2067 -- nice guy, quality service.

For synthesizers I don't work on (Moog, Roland, etc) check out Chris Hewitt at This Old Synth -- http://thisoldsynth.com/

excellent reputation.

The best MIDI for the Pro-One (along with new CPU chips) can be found at Music Technologies Group -- http://www.musictechnologiesgroup.com/index.html

--lots of other interesting things as well.