Today I started rewiring the nav lights and found they have used 2.5mm domestic cable up the mast!! OK that will have to stay for now but I have put waterproof connectors at the mast step and run new marine cable from there to the switch panel. If the mast ever gets removed or I need to do work up top, the wires can be replaced then. Domestic cable has been used a lot on the boat, the reason why not to do this was seen on one cable where the copper was tarnished at least 2 feet back from the end cut. I also finished recovering a bit of headlining, I only did the worst bit, the rest of the headlining will be replaced in a future project.