You could carefully take some of the flange depth off.
I have a 2-railed Lionel B6 - rather than risk pressing those beautiful drivers I mounted it on a compound table, shielded the motor, and turned it on. A sanding drum brought those wheels down for steel tire installation. No wobble!
I forget how I mounted it, but a wood fixture is good enough. You need to carefully protect the motor from ironand abrasive dust.