Mid century Marbro Amethyst lamp

I recently started working at an estate sale company and have actually found it has helped be be more particular when buying items at these sales, mainly because I have more time to look over the items. Today I found what I believe to be a vintage amethyst Marbro lamp from the 1950s. Photos have proven difficult in capturing the lovely purple color and an interesting crackle effect that looks like frost crystals on the inside. The original brown lamp shade didn't quite look right so I changed it to a neat fiberglass one.