This is a porcelain whatisit described as an insulator by the eBay seller who found it in a barn in Centralia, WA. The porcelain cyclinder measures 7 inches long and 2 inches wide in diameter and appears quite old and crude. There are 5 holes that go completely through the cyclinder.
I ran it by two retired lineman/insulator collectors: Dave Potts and Ron Jenkins, and also Bill Rohde at the Roseville Show, but it remains a ????. So what is it? I posted three more photos [id=517415390] [id=517415547] [id=517415659]