I am searching for info on how the ACL and subsidiary Charleston & Western Carolina used their headlights. The arrangement in my photos and research shows two sets of lights for F7s and GP7s. In the F7 door light and lower housing of the GP7 is the standard hi/lo headlights. The upper housing (F7 nose/GP7 both ends) above the headlights has a red Gyralight with another light above it in the same housing. Can anyone explain how the red Gyralight was used (reverse running, grade crossings, etc)? What was the color and function of the light above the Gyra? Thanks!