Does it have a lever for forward or reverse? if so it is a series wound motor, but i think it is more modern and has a sepex wound motor meaning it has a electric switch for F&R. Does it have a amd motor?
Motor looks to be in bad shape, why is controller unplugged ? If both are bad i recommend not spending the money to fix. That particular motor and rear axle had many problems with snapping the axles, replacing the motor is impossible, no one in the US makes that flat mounting plate style motor so you would have to find someone to rebuild it. Replacement axles are no longer available.