@Ncore, I found the same in my red type I motor.
I seems that in the original casting moulds A and B were reversed - but it's not known if the letters on plastic housing or metal parts are correct.
For type II motors, this has been corrected. There is a rectangular elevation around the letters A and B, which indicates an insert has been created for the original casting mould.
And creating an insert for a plastic die casting mould must have been the cheaper option than modifying the casting mould for the metal parts..
I found another interesting deviation: My red type I motor has metal cogs on the wheel shafts.
Anyone seen this as well?
Perhaps it is linked to the production date. My red type I motor shows date code 16 0 on the bottom side.
FYI, @Reza started a thread on date codes for bb0012vx motors.