This piece looks to be hand forged to me, it was nailed on the top of a 1901 power pole and the hook at the top end originally held barbed wire, which was supposed to serve as the ground wire. From what I have been told, this arrangement was soon found to be unsatisfactory, as the barbed wire proved to be brittle so frequently broke. Very hard to find, I got only two in a summer's hunting, $25 ppd. US or glass trade.