Orginal Kaiser 6551 Idell desk lamp

This is an original Original Kaiser Idell desk lamp, model 6551, they were produced in the 1920s and 1930s, as you can see, it is not in perfect condition, but I think it is still quite good, considering that for a few years my father had it in the garage and I had it on my desk. I've had it since I was 5 years old. It was only recently that I was tempted to check what kind of lamp it was. It does not have the original switch.