I got a bunch of these 6V emergency heads from my grandpa a few months back and they've just been sitting on the basement couch in a trash bag waiting for me to do something with them lol.
Then it occurred to me... I could install an E12 socket with a hickey mount (the O-ring that threads onto a 3/8" hollow threaded rod, which is what is used to attach the head to the knuckle bracket, so it would work perfectly). I had some polycarbonate sheet leftover from my brass PL13 box light I mounted to my shed so I cut a circular piece out for one of these and it works well (it was thin enough to roughly shape it with tin snips lol). I took sand paper to one side to give it a frosted look but will look into ways to give it a more uniform frost (sandblasting perhaps? Can't easily get my hands on equipment for that though...)