original early 20th century american industrial single arm wheeler copper wall sconce with impact resistant shade

hard to find all original c. 1930's minneapolis grain elevator wall-mount "explosion proof" sconce with rare threaded copper fitter. the single light fixture was fabricated by the wheeler reflector company, chicago, ills. the sconce retains most of the original green paint over copper. the cast iron flange and elbow joint are original. the socket is housed wihtin the impact-resistant bulb guard.