I recently purchased an insulator collection and these porcelain/metal "rolling pins" or what resemble rolling pins were in with the insulators. I don't know if they are insulator related. The center portion is colored porcelain. The protruding pins are copper on two and aluminum on the third. They are embossed FARGO with a lot of numbers and letters. The pins do not go all the way through the porcelain.
Many thanks to the several people that answered my question. It looks like they are porcelain devices for splicing a line while breaking the circuit at the same time. When a wire is inserted in the end it is locked into place.
David Dahle sent the following links: http://www.ipernity.com/doc/ndlinegeek/18181893 & http://www.ipernity.com/doc/justin.schlueter/35241247