Is it truly a post-war or mpc/LTI #192 Control Tower, or a more modern one that doesn't use the washers with fingers? (does it have a rectangular gearbox underneath the men on the underside of the room the men spin around in?) The exact model number would help here.
If it's a more recent one, it sounds like the wiring maybe got crossed at the motor. I couldn't find an actual service manual with an internal schematic on Lionel's site, but I'm pretty sure these are DC motors with a diode on one leg to make it spin in the proper direction. If the diode is on the wrong leg, it would spin the wrong direction.
(I intentionally did this years ago for an airplane pylon to get it to spin "backwards" (after having of course also made an adapter to have the plane sit backwards so it wouldn't spin tail-first 
)
-Dave
