What is the type of this legacy motor and how is it supposed to be controlled?
If it does not have a commutator it is not an AC/DC motor. It will be a single phase induction motor. Universal motors have a commutator and the field is wired in series with the armature. Universal motors resemble the series DC motor in their construction. They are sometimes called AC/DC motors.

If your motor has a commutator that has its brushes shorted and the mains going into the field then it's a repulsion motor, which are popular in the USA for their superior starting torque compared to other single phase induction motors. From what you have drawn I think you have an induction motor.