Indicator LED for Diaz Tremodillo

[Mark Hammer]

Someone posted a request for how to mod a Diaz Tremodillo pedal to have an LFO rate indicator LED.  I can nurse the guy through what might need to be added, but I lack the requisite schematic.  If anyone can direct me to what spot on the board should be sought out, or a legitimate (and verified) schematic, that'd be great.  You can post here or PM, whatever you're comfortable with.