Repair a Superphon Dual Mono Pre-Amp

I'm looking for someone that is familiar with the SUPERPHON REVELATION dual mono PRE-AMP that is technically skilled and can implement a repair. The pre-amp is in perfect functional condition so far as I know with one exception. The "MUTE" function does not work. Unfortunately, the failed default condition is "off" and not "on" so this difficulty is causing the pre-amp to be non-functional. I have been trying to get a line on STAN WARREN, the designer, with no luck. Even someone who has a schematic for sale would be helpful. This is a great pre-amp that I would like to be able to use again.

Try The Stereo Doctor in Dublin California. I have had him repair lots of stuff and he is always top notch. BTW, repair is all they do, this is not a retail outlet although he does have used gear for sale there.
If your red led comes on after about 30 seconds you're good. Just open the top and re-solder wire(s) to the mute switch (mine is a Revelation II with balance control, but there's a pic of yours on Audiogon that looks to have the same setup.) If the led doesn't light there's probably something more complex going on with you system.
Just checked and the led goes off when mute switch is off, so you'll have to open it up anyway to determine if it's a break at the switch. Had to resolder my rev ii.