An old 10inch porcelain insulator.

I recently came across this old insulator. I have not been able to find a photo of it anywhere. I collect a few odds and ends and would like to keep this in my collection but I dont know anything about it. It has the brown crown, followed by a 10inch ceramic dish like, followed by an 8 inch another ring of grayish material. It comes on a 18 inch bolt/rod with original nut. Does anyone know anything about this. My personal phone nr is 601 798 6594 if you have any history and thanks in advance.