Z Axis feed control ?

I'm converting an old NC controller (and a Spindle Wizard) on a
Bridgeport to CNC with the existing stepper motors.

On the old control panel there are two potentiometers labeled "%
feed" and "dwell".

Does anyone know if I put the "% feed" pot in seriies the the DC
voltage feed to my stepper controllers if this will allow me to
manually control the top speed of the Z axis motor?

Also, does anyone know what the dwell pot is for and how it is
supposed to be connected?

There is also a 3 position rotary switch labeled "Rapid", "Feed"
and "Auto". I assume the rapid setting bypasses the "% feed" pot and
the auto setting goes through it. Don't know what the feed position
does (unless it was originally for a manual feed capability with one
of the many unmarked push buttons on this thing). Anyone able to
confirm (or deny this)?

Thanks much,
Jeff