You can't get 14 volts from ONE post. The 14 volts is between two posts C-D. You have your Newstands connected to the D post. The other Newstand wires go to the U post. One wire (light) goes through the Lockon rail (U) and the other (Newstand operation) goes through the insulated rail which connects to the other rail (U) when the train passes.
You can't wire the Banjo to an insulated rail using the 14 volts from C-D.