X350; Radio rear seat switchpack

Has anyone investigated the interchangeability of the rear seat arm-rest switchpack for the radio?

I’m asking because one of my club members has established that when we disconnects the pack, the rest of his system works. When re-connected, he suffers various faults.

Trying to source one is proving to be a challange but, I have managed to find one out of an X351 (2008). The question is: will we be able to connect it in this 2004 model?

Kind regards,