As I have recently explored some buildings that used magnetic rapid start fluorescent luminous ceilings, I am starting to wonder if any buildings in North America used any fluorescent luminous ceilings that utilized preheat fluorescent fixtures that were diffused by plastic or glass panels that were attached to a metal grid?

Benjamin probably had such a system. They marketed the Sky-Glo line of illuminated fluorescent ceilings as early as 1948. Here's some details from a 1952 catalogue. By then Benjamin has two lines, the Sky-Glo and the Grid-Lite which was designed around slimine lamp.