I just got a new pair of Nordstrand NJ4 pickups after a friend got them a few months ago. I notice a few differences, although it's the same model. His set has three wires (an additional one is coming from a copper tape attached to the bottom of the pole pieces). The pole pieces for the A & D strings are higher than the outer ones, following the neck radius. The plastic covers were rounded with matt finish. Mine have only two wires, all pole pieces are the same height, shiny covers not rounded. Anyone knows if these are different, older/newer versions? Different specs?Can I add the third wire by myself, do I need to? Thanks!