Interesting.
I am going to guess its a Frankenlamp
The shades are marked Laurel per your photo but it has 2 types of swivels, what you referred to as brackets, (one being a K&L!) and the base and main section look like Lightolier (or similar period manufacturer).
I would be willing to bet that it looked a lot different originally and someone made a series of "repairs" in order to prep for sale.
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