Not exactly an "auto-wah", but by itself, these project shots (not mine BTW) are of a pretty spectacular cocked-wah circuit with an expression pedal. So basically, this is a "brains box" for a super wah expression pedal. The main board & stompswitch PCBs are GuitarPCB boards. The Fasel board is Vero and the two 6-way rotary switches & PCBs are from SmallBear. I'm sure of all the in & outs, but this project looks awesome!
I've had a project similarly conceived and has been in parts and notes collecting for a couple years now, but no where near as elaborate as this one. I'll definitely be taking some hints from this one.
I get the impression that somewhere between the Dipthoniser (Honey Dripper) and the "Howling Shiba Deluxe Wax" (shown above) should be able provide a close enough proximate to what you're after.