Re: Fuse board
The nice thing about those 1-2 or both switches is the contacts slide together ,so if they get a bit of corrosion on them, you just have to switch them over and over again ,until they wear the corrosion off.
I got sick of the positive side of my fuse block corroding, so made my own fuse block out of titanium. Zero corrosion since.
Brent Swain, Yacht designer, Builder, and author of "Origami Metal Boatbuilding"