Is the trolley recent? I'm not sure Stan has the postwar version in mind. The more recent versions use a small dc can motor; the pw is a universal open frame ac motor.
What I have in mind is a method to use his trolley as-is. All electronics or modifications will be external to the trolley. It will use the existing bump-n-go mechanism for reversing. In other words, it doesn't matter if the trolley guts are a DC motor, an AC motor, a mouse running on a wheel, a rubber-band, or fill-in-the-blank.