I still don't know what to make of this piece but assume it is of Soviet-area origin. This is this first piece I've encountered with a fully cemented pin-hole and a threaded steel rod and I have no way of telling if there is a threaded or threadless pin-hole or even an inner skirt or not. The piece is quite heavy and has a very creamy off-white glaze and is unlisted in the newest edition of Worldwide Porcelain Insulators.

Does anyone have any information on this piece?

Thanks for looking.