I don't really know the best method for the filters but I had to give up on the method for volts per octave given in the service manual as it was getting me nowhere when I replaced a CEM3340 recently.
I finally busted out my peterson strobe tuner and tuned it the same way I'd inntonate a guitar. First I would put the master in tune for the lowest C. Then I'd go to the Volts per octave pot and put in tune the highest C on the keyboard. This will throw the master tune out of whack. So repeat. You should see a closing of the gap with each repetition until you are seeing the low C and the high C in tune. It might take 3-10 times doing the cycle.