Most of your switches are actually breaker/switches, push-button switches that are push for on, push again for off & if overloaded it will pop out even further. These are not available in momentary switches like a horn button or ignition switches with multiple positions. So where a breaker/switch is not available we used a panel mount fuse to supply the power to the switch. You are referring to the fuse for the horn switch circuit. I am stocking the breaker/switches & have some stand alone fuse holders. Is your fuse holder corroded or do you just need a replacement fuse??