The digits of Lucas part numbers hold no significance.
I see that the electrical specs on the AC (Malta) Mk V show a 75664 wiper motor...so that should be encouraging.
The only thing I have personally seen as variations on the versions of the DR3 is that some part numbers have a connector on the motor body...and others (the Cobra-correct ones) have the short pigtail wiring harness as part of the motor.
