Ever since I got my Drovers Caboose I wanted to illuminate the dummy Marker lamp on the roof of the cupola, I did it today.
It wasn't as hard to do as I first thought. I used .092" brass tubing, the inside diameter is .062" or 1/16". I cut and soldered the brass tubing to form a "T" the same size as the original Marker Light. A 1.5 volt micro bulb just fits inside the tubing.
I removed the lenses from the original light and glued them on the tubing with LOCTITE Super Glue. I will also add a 1.5 volt interior light and a few loggers guys sitting and a caboose guy standing on the rear platform.
I wired it using my standard 1.5 volt regulator circuit powered from the rails to charge a NMH 400 mah 'N' cell battery in the freight/baggage end of the car. I used the caboose heater stack attached to a brass rod to operate a micro switch to turn the power off to the lights by rotating it 90 degrees. The battery maintains a constant voltage to the lights for a more realistic look.