On the back of the panel, look specifically at the unit that is screwed to the front plate… The bit with the buttons on it…
There will be ID markings, and then google will be your friend in finding a supplier for the part. Farnell UK is a good source of stuff…. I got some of the lit 240v switches above that panel a few years back…..
The membership association for owners of Dufour Yachts