The refractor unscrews from the fixture. I guess the gasket is made of asbestos. Maybe someone can help date this fixture. I've been working for the utility for 26 yrs and they have been there for as long as I worked here.
Well here's one hint of how to age it....it has to be the 60s-early 70s or older since 1980s and onwards the medium base became more available although they did exist in earlier days, and since they are mogul fixtures for such small fixtures, this is where I am guessing the age....They are internally ballasted right?
I don't think so as it looks like a weatherproof outdoor recepical box and they were used because those are newer than the building and was installed later instead of making big holes on the bricks and wiring behind the bricks, so they used EMT and outdoors connectors and couplings for wires to go through and outdoor boxes. my guess is on the top.