Component side of RJ45 to 4 searchlight signal driver card.  As it turns out, four signal heads are typically used for an OS section at the end of a passing siding, so the 8-wire (2 control lines per signal head) cat 5 network wire seemed like a perfect match.  The brass screws are for connecting power and ground to the board.  The trimmer pots are used to adjust the quality of yellow on the bi-color signal LEDs.  The blue connectors are used to connect the signal wires to the board, however, these connectors are little too big to sufficiently grasp the small magnet wire used on the commercially available signals.  Therefore, before installing the the signal, I solder a small piece of 28 AWG wire right at the end of each signal wire, so the clamp in the blue connector is able to grab onto the wire.  The 28 AWG wire is still small enough that I can feed the wires through the small signal mounting hole in the layout.  Therefore, I don't have to do any soldering under the layout once the signal is installed.