Vintage Table Lamp

I'm an electrician so I'm sure this was some sort of table lamp. To me it looks like it would have been for industrial use. There's no markings at all but looks like it would be from the 40's possibly. The inner light socket is missing but there are some rust stains on the threads. It has threads for a shade but I don't know if it would have been a bullet shade, like industrial type dust proof fixtures although I could imagine it having a white globe shade or something. One problem I'm having is finding a shade that matches the thread pattern because they are very course, a standard thread pattern on threaded shades are a little finer like those on a mason jar. It looks like it's made out of porcelain and measures 2" H x 4 5/8" W. The threaded shade opening is about 3 1/4".