I found this insulator while cleaning out one of my storage bldg. and wanted to know what it is and if it is worth anything. It is brown and Light grey, with the following stamped info: 5-3, a big C with and 83 in the center of the C. It is approx. 4 1/2" across the bottom, and 3 1/2" across the cradle at the top. It has a splat of some thing spilled on it that is sort of gritty didn't want to try and sand it off for fear of damaging it. It is a screw on type insulator.