Thanks for the guidance. Yes that's correct, there is a cage that is soldered into the pcb board that holds it in as well as the 6 legs. So as you say I should be able to keep the original 6 pins in and solder an after market one to the existing legs.
Thank you for the link for the manual too
I'll have to find a uk site version first. I have previously completed a thread about changing the sens slider on the panel board with some macro images. Will do the same with this thread. I've already labeled the wire harness inside the synth and it's still 3/4 stripped, so it shouldn't take long to take her apart again