Bill.
I can't help with the Mute switch but I had an F1X that someone had simply extended the wires on the on/off switch and moved it to the front.
If you put a rackmount tuner in the effects loop, you can use a latching on/off footswitch on it to kill the output from the tuner. This will have the same effect as the mute button found on normal preamps.
Graeme