Filigree slag glass lamp

Anyone know anything about this beauty? It’s a family heirloom of my great-great grandmother. It does not have a makers mark that I can find. All glass is original, cord is original but in very poor shape. I’m trying to at least date it and find an approximate value of it. Have found 2 others online with slight variations but was unable to obtain any info on them. This one has a lilac color in the creases is the metal that appears original. This lamp is a mystery to me!