It always amazes me just how little information is known about many older products/wiring systems etc. when really they are not all that old.
I definitely wish I was around to install some of the stuff though, the photos of some of the installations look amazing, huge motors and their floor standing cast iron control units, loads of steel conduit, big open fronted fusboards and control panels, huge rheostat and salt water dimmers and elaborate electromechanical controls. Almost everything now is lifeless boring flimsy plastic crap.
Not to mention the amazing lighting that used to be available, gas, carbon arc, neon/sodium/mercury discharge, carbon and tungsten filament. All we really have now is LED which OK but not very imaginative. Some of the photos of the lighting (and general building/decorating designs) in the 30s are spectacular, such designs and creativity are almost impossible to achieve today.