Nice work.
I could see this wah modding continuing to a pot or rotary to set the sweep frequency range, a resonance control (is that possible?), maybe even an lfo or an envelope follower to supply the control voltage. Adding a Morley-style LED/curtain system to work as a secondary variable resistor so the treadle could be used as an expression pedal to control another effect at the same time - that would be interesting. The possibilities are endless!