You've got the uModII already? Well, don't let it go! I've thought for a while that that was a superior piece of gear, especially due to the separate "SUM" and "DIFF" functions. Most ring mods don't let you go there, and if you can find a quadrature VCO to pair with it, you can get fairly close in behavior to a Bode Frequency Shifter. Not spot-on, but pretty close.
-- Lugia

Thank you @Lugia for your insights. Excited to try it. Trapezoid Thru Zero Quadrature VCO by Doepfer as a pair to uModII?
-- Iheartopone

Absolutely! While it's technically an audio source, that module would work. But a better quadrature modulation LFO would actually be Doepfer's A-143-9. Having that sort of phase-shifted modulation is an awesome tool that can work in a lot of places...effects, autopanning, stereo level modulation, and on and on.