Etched the PCB tonight, so I will probably be up and running soon. (Had a test circuit on a protoboard.)
A thought or two- based on your scope traces, it looks like the gain of the tube circuit you emulated with the bender is about 60X. That must be unloaded? In the tube Fender, the first stage is loaded by the tone stack and the gain is more like 43X. (going by the AC voltages off the Fender DRRI schematic, 37mV in =1.6V out) So, maybe better to adjust things to more closely emulate the original?
I'm guessing that your design process was to note that the tube circuit swings about 200V pk-pk at the limits, the op-amp/jfet is limited to 30V or less pk-pk by the 15 volt rails, so the gain of the op amp stage has to be scaled accordingly to get the right headroom. 200/30= 6.6, so using your gain of 60X, the op amp's gain should be 60/6.6= 9X . I may try revising the gain of my build down, as the op amp won't get loaded down at all from the tone stack due the OpAmp's low output impedance.