Yes, the boards are in the tender, and there is an output that's active on every sound file I've used for the reverse light. It's possible the Molex connector is there and all you'll need is the little light cable, but you might have to add a wire from the the 12-pin connector on the PS/2 board. The rear light is connected to PV pin-2 of 12-pin connector and pin-4 of the 12 pin connector.
The bulb is a 6V incandescent, or you can use a white LED with a 220 ohm resistor, positive lead of the LED to pin-2 of the 12-pin connector (PV).