I mentioned "ground lights" earlier. In later years, the SD40-2 years, ground lights were replaced by Step Lights that illuminated what else but the STEPS. It was seen as an aide in helping employees find the steps in the dark. The concept of step lights is identical to that of ground lights. These were normally extinguished on trailing units in a consist. Several other locations were illuminated also in the effort to provide a safe work environment for employees required to walk on and around locomotives in the dark.
All locomotives have safety lights at various locations for obvious reasons and these locations vary on each type of locomotive depending on the builder. With fiber optics it would be possible to duplicate all of the lights on a particular unit and would make an eye-catching model when viewed in the dark. One or two engines, so equipped, could be designated as "Lead" units in multiple unit consists and used to "show off" the details so often omitted from models. Lotta work but should prove ta be an outstanding model.