Thanks RBM,
I plan on going with a 20amp 240V disconnect along with matching outlet
and plug. The wiring had me confued because I did not know that a 240V
circuit does not need a neutral and rather each hot wire trades off as
being the neutral. I kept banging my head about how the electrons will
flow back to the panel, but now I know. Now the white/neutral wire can
be used as a safety ground so long as I label it as such (green tape)
at the outlet and panel. So the red and black will go to the line side
of the pressure switch and the white will get attached to the housing
of the pressure switch because it is close in proximity and common to
the chasis of the motor. Do you think originally the plug would have
used the white/neutral wire as a safety ground? A consumer would not
have known to label the outlet/panel with green tape back in the early
70's when this compressor was bought...don't you think?