This oddball porcelain insulator has been sitting on a shelf behind the counter of an antique store for years and was NFS every time I asked about it. My wife finally convinced them to sell it. I'm guessing it's possibly a foreign radio standoff. James Lindsey told me it was made by the Cook pottery company which operated in Trenton, NJ from 1894 to 1929. They made lots of electrical porcelain insulators including tubes, knobs and standoffs