This is the socket that removes the Zinc locknut from 1948 through late 1960’s Crane Drexel and Marcia sinks. No need to remove the street 45, this fits over it. Insert a heavy Phillips screwdriver through the holes on the backside, and give it a good twist. Unit is 4″ long.
Note, this socket does not work on the early Drexels with cast brass locknuts. To tell the difference, scratch the locknut with an Awl. If the base metal is yellow, the nut is brass and this socket will not work. If the metal is silver (and this is far more common), then the base metal is Zinc, and this tool will work.