That 120a motor is approaching 6hp, it is unusual to see a motor of that HP at that voltage, unless it is a traction motor used on mobile equipment.
In that case, you should check to see if it is a wound field series motor, if so, even if you find a controller for it it, a series motor will not work for this application.
(you will get run-away with no load).
Al.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.