Vintage Crystal Lamps with Silver plated base, top, harp & finial

I'm trying to identify these lamps with no luck. I cannot find any markings anywhere. They are very heavy (about 9 pounds each) and measure 31" to the top of the finial. All of the metal was very tarnished, yet polished up beautifully with silver polish, so I believe they are silver plated. They have modern Levitron cords, but I believe they are old lamps. Any information would be greatly appreciated!