This came in a box of things. It looks like an Ohio piece but, there is no brass plate on the top of the arm where the screw comes up.

Arm is 10 3/16"  long. The outside of the threaded section is a fat 3/4" in diameter. The outside diameter of the bell-shaped nuts is 1 3/16" in diameter. From the center of the threaded arms to the upper side of the fence, the dimension is 1 5/16".

All components appear to be Turkish Boxwood.