Danny, your list of classroom aids omitted the most important one of all, the Chinagraph pencil. Without that the Royal Air Force might never have survived. Certainly it would have complemented your White Boards and projectors. In combination with that other triumph of democracy, clear Fablon, it meant that pilots could reuse aviation charts with DME range rings drawn in before the product was carefully applied on top. Planned routes could then be drawn in Chinagraph on the Fablon, with fixes entered en-route for DR heading and timing corrections.
The most vital application was however the all important Org Board. Every Authorisation room, every Eng Control, every boss's/adjutant's/adminer's office was festooned with them. Sheets of perspex mounted or hung on the walls covered the required tabulated layout of columns and rows whereon the data was entered. If there is not a chapter in the Official History of the Royal Air Force not dedicated to that one item then I am afraid that it is sadly in want. Each colour was of special significance, and much was the woe if the blue or whatever colour could not be found! Unlike computer records these days which are saved, backed up, and claimed to last for ever, the entire board would be wiped clean with a cloth and a strong smelling solvent (no doubt also bearing some copy write trade name) at day's end, or whenever, leaving a blank board for refilling next day.
A technology as important to Air Power as any aerodynamic or power plant breakthroughs, yet when was the last time you saw a Chinagraph pencil?