I play in a Boston tribute band and I use a pretty simple set-up to replicate Scholz’s tone.
A Dunlop Q-zone pedal for the “parked wah tone” gets me the rhythm guitar tone. It works well because I can blend the wet-dry signal in order to not have the effect becoming too overwhelming.
For the harmonized solo parts, I use an Eventide H9 with pre-programmed settings in a loop that I activate w/a momentary looper pedal. I apologize for not sharing the exact details of the settings. I need to keep things somewhat ambiguous. I hope you understand.