Firstly your switch doesnt look like a reversing dewhurst type switch, it looks like a 2 speed selector.
Here in the Uk the colour code may well be different so what I say may not apply.
The red & black or A & Az are usually the run winding, the other 2 wires going into the windings part of the motor are most likely the start winding, I see in the pic there is a centrifugal switch.
Reversing the polarity of the start winding in respect to the run winding reverses a motor of this type, to do this you need a double pole change over switch, it may be possible to do that with the switch you have, you'd have to check it with a continuity tester to find out what contact arrangement it has.
You should also meter out the windings of the motor before you try to run it.