Another Unidentified Motor Crisis!

[MrForbes]

That's an old BaneBots motor and gearbox, which I think came in the 2007 kit of parts. The motor, you could check the numbers, and if you still don't know, you could use a new RS550 type motor to replace it. The gearbox is an old KOP and COTS item, so it should be legal. You have to remove the pinion gear (or buy a new one) to be able to change the motor.