I think I have misspoke and confused you. Looking at your era schematic, I should say there is only one power input to headlight switch.
As you probably know, that wire going to the tail light fuse is an output to the tail lights. My apologies. Schematic shows one power wire in from ammeter and the rest are outputs. They show the tail lights and the stop lights going thru a fuse on their way to the lights. I guess the rest is fused by internal protection. So one hot wire into H/L sw. All others are outputs to various lights. Some of the output wires go thru a fuse, then to the light. These would be unswitched fuses.
"Thru their switches" means: in one side of switch and out the other..
The components with switches, as I mentioned, would be wipers, heater, ...anything that has it's OWN switch. NOT the IGN switch.
In other words, a wire from a switched fuse to the wiper switch "in" terminal, another wire from the switch "out" terminal (you just went "thru the switch") then that "out" wire goes to the wiper motor.
In this case the ignition switch would have to be on and the wiper switch would have to be on to operate wipers. (you may have vacuum wipers). If a person has no electric switches on the dash except the Ignition switch, the comment would not apply. The comment was a general wiring comment.
These switched fuses would also be wired to gauges, the coil and components that don't have a switch and use the ignition as their switch or as you decide.
