from the GUS man himself - Simon
Just as a bit of extra info, I mostly use Graphtech Piezos and circuitry now for the midi guitars (images attached) as I prefer the way their saddles integrate into me bridge design...little black graphite encased pickups that look very neat as well as sounding sweet.
and another excuse to look at a damn fine guitar
don't think this is the only information
plenty of amazing images and information at the link below