Dear John, thank you for your interest and advice.
I am actually not an electronics technician either and my skills only go so far.
So far, thanks to Rudy’s (Beolover) advice and tutorials I have managed to solve “everything” except the STOP button which still does not work. As soon as I have some time I will try to disassemble the pad and work in the contacts with sandpaper.
Have a good evening and thanks again,
Luigi