This is a solution for guitars with deep barrel jacks.  The Switchcraft Switchjack has four lugs like the Stereo Switched Jack that comes with the Acousti-Phonic, but the switch works in the opposite way, so it can't be wired the same.  This wiring delivers both Mono and Stereo modes.  Note the Switchjack is designed for acoustic guitars and comes with a strap-nut, but this can be removed and replace with a regular but for use with electric guitars.