Looks like the three chorus sections are identical so if you trace one you get them all. The vactrols are might be for the three intensity knobs if I'm guessing. Taking the output of the LFO to split it to the three clocks maybe?
That is correct. The chorus section looks like are the same with different calibration

those trimmers adjust the DC offset going into the BBDs and adjust the center frequency of the VCOs for the clock oscillators. Same as the TSC.
The optos are for the manual LFO for adjusting the frequency and to make it a sine wave oscillator. Also same as the TSC.