The 961 Sequencer Interface was moved to a Console Panel in the Moog System 55. It is nearly the same as the 961 module (only a single S to V trigger) with the PCB mounted separately to the bottom of the cabinet. The 961CP consists of two multi-channel V-Trigger to S-Trigger converters, one S-Trigger to V-Trigger converter, and an audio to V-Trigger converter. Complete details of the 961 are on the 961 Sequencer Interface page.
There are four tabs mounted on the PCB to attach it to the bottom of the cabinet. The timing was considerably different from the front panel markings. Calibration could make the markings agree but at only one setting. I ended up calibrating to 500 mS and then adjusting the maximum resistance for 4 seconds. This required some trial and error as my modifications changed the taper of the control. I was able to make the markings reasonably close to the timing.