Ironically, the HS-572 switch seems to be available everywhere except Rock Auto.

Car ID: https://www.carid.com/standard/intermotor-hvac-blower-control-switch-mpn-hs572.html

Summit Racing has it: https://www.summitracing.com/parts/SMP-HS572

1950 Chevrolet 3100 (Ol' Roy)

1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)