Thatheadlight switch mess is a result of excessive heat from corrosion and or lose connection. Corrosion acts as a resistancein any circuit; resistance = heat. As forthat switch, it is in a spot that can get wet from leaking windshield or wiperbushing. Also while investigating forwater damage make sure fuse holder and fusses are corrosion free to eliminateany additional problems.
Headlight circuitis one of the high draw circuits in these old cars. In addition to under dash corrosion abatement,pull headlights, and make sure each ground at bucket, and three conductorconnector the attaches to head light is free of corrosion. The headlight ground needs a good clean connectionto front sheet metal.
The bestsolution to correct poor headlight performance is to install a relay system poweringthem directly from battery with #10 conductors, and triggered via headlightswitch circuit. This removes highcurrent draw through headlight switch, shortens current path and voltage drop tolamps resulting much improved performance, and cooler under dash components.
