Just bought this

Does anybody have any idea about when this was made? There aren’t any manufacturers marks except what looks like a 1 on the metal base. Cant find a list of manufacturers from the Art Deco era that used spelter. It is not magnetic, and it looks silvery when you look into the bottom missing the felt, and where there is a tiny chip, which is why I’m assuming that it is spelter. It is extremely heavy, and beautifully made, and definitely an older lamp. . It had a very expensive cloth shade on it that I replaced as it wasn’t my taste, though I kept it. Looked at many sites, and most Art Deco lamps are more ornate, unless it is not Art Deco at all. The molded metal portion is 17 1/2 inches high. With the shade it is about 30”.