There is another builder/designer Jon who has experimented with a number of my compressor circuits. He recommends a lower value for R1 of around 22k instead of the 100k in the schematic. This will lower the max compression a little, but will help with stray capacitance roll-off of high end. It should work fine. It will load the guitar pickups a little with heavy compression. Also the diode peak detector is biased in a more linear range by changing R8 and R6 from 470k to 47k and C7 from 1uF to 10uF. I think these values will work a little better.
Over my choices are: 100K for R1, 47K for R6 and 10uF for C7