Just a thought and no apology if I am stating the obvious; it is obvious if you have been around wirewheels before.
Look at the arrow on the face of the octagonal nut on each side of the motor, note that they undo in the direction as the wheel travels forward.
The right side is different to the left side.
For RHD motor:-
Nearside undo - ANTI clockwise
Off side undo - Clockwise
+1 - MOCA have a great tool too - basically has a longer handle (that is kinked) than the normally spanner...
