early CRESCENT handheld portable electric work light

This is a really cool old 'trouble light/drop light', maybe from the 1930's. (?) The remains of its original label identify it as a "CRESCENT PORTABLE LAMP GUARD", though the parts of the label with the exact mfr's company name and location now can't be read. It features a long cloth-covered twisted-pair power cord wire terminated with a brass/ceramic/bakelite connector made to screw into a light bulb socket instead of fitting into a 2-prong wall outlet. That connector is interesting in itself, its outer brass 'threaded' part is fastened to the outermost ring of its black bakelite housing with a swivel mechanism such that it can be screwed into a light socket without also actually twisting the power cord wires themselves. The brass bulb socket within its cage has a rectangular turnkey knob labeled "ARROW".