The top left faders are for controlling the arranger accompaniment levels (drums, perc, bass, etc) and the top right faders are for controlling the left, right and second voices. The other 4 are for the Master Volume and part Mixers.

It will have a set of 20 drawbars (9 + 9 + 2) for controlling a virtual Hammond VSTi - but I didn't lay them out for the image above because they interfere with positioning the buttons on the bottom right of the panel.

They are shown in post #423431