This Hammond X2 came in a weird shape, it was basically working apart of last octave, upon opening the organ I could see there was somebody there before me. It was modified to add pedal octave mod. It was done sometimes during 70s or 80s in Czechoslovakia and it was predominantly made using integrated circuits from eastern Germany. I was for a while contemplating fixing the mod but after discussion with owner it was decided to chop the mod out and revert back to original design.
This extra board (impossible to read any labels but ended up being dividers) creates the pedal octave and the smaller board with double VCA and two transistors mixed the pedal octave and lowest octave together. Rest of the issues were down to thorough cleaning of switches and contacts.
It took me a while to find the service manual but at the end I managed to get hold of it.
Here is a link for those who might be in the same situation