My band just started covering this tune. It's not really using the effect labeled as Ring Modulator, but a cousin......Wah Freq Shifter, and it sounds more like the recording IMO.
It's sounds pretty darn close to my ears when you play the octave C notes at the end of each chorus and finishing with the G and C diad (3rd and 4th strings at the 5th fret).
I put it in Stomp A.
Wah Freq Shifter
Manual: 6.9
Pedal Range: 0%
Pedal Mode: Bypass @ Toe << (my own preference to pull the effect in and out quickly)
Mix: 100%
Ducking: 0.0
Volume: 0.0