All,
It would take a lot of current flow to blow a Delco switch. Especially to burn through one of those contact arms. I'd speculate a dead short somewhere. A bad ground would cause inop lights, but I don't think it'd burn the switch.
Do you have High-Beams? Circuit runs from dash switch to "dimmer switch", then to headlights.
FWIW, I'd use dielectric (aka: "tune-up") grease for electrical connections after cleaning them up so that nasty corrosion won't happen again. I doubt corrosion is the cause of your burnt switch, but it sure doesn't help the flow any.
John
P.S.
Have you compared the connection placement to the switch on your 59? My original switch has a contact marked "PL", but that's for the "Panel Lamps" and that is the circuit the attached fuse on the switch protects.
