Glad to see this thread has come back to life!

I think I remember the Air Raid Drill Signs - were those the ones in the basement, and were they black and yellow? Or maybe I'm just remembering yellow/black stripes on the walls that helped make the walls more visible in the darkened conditions. I know there were the other signs that said "Fallout Shelter" - by the stairwells, right? And I remember in the basement they had room numbers painted on the walls as well - not sure if those were "just" to designate where specific classes were to gather or if they actually were geographically directly under the rooms they represented.

I absolutely don't remember any "Fire Drill signs." Wonder if anyone has any pictures of those?!