Vintage Metal Desk best Lamp, Library Lamp

This is pre owned and used. I cannot fit a regular bulb in to test it. It takes a cylinder oblong bulb so it is not tested and sold as is. The end you screw in looks best like a standard size end. Top shade is 9 3/8" x 1 3/4. 12-14" tall. Base is almost 6" side to side. There is heavy age discoloration and rust spots on the metal. The metal is non magnetic and looks like brass but I am not certain. Unbranded.