Side view showing the positive pickup lead from the tender soldered to the tag at the bottom of the vertical copper strips. The red lead is painted black here as it will be visible when the body is put on. The 3 layers of plastic card and the adhesive pad can be seen clearly in this shot. It looks like I used N Gauge brick wall for this job !

Note the underside of the screw hole. The worm gear is directly under this hole. If the screw is too long, it will foul the gear.