Here is a wood "insulator" that appears to be a slot top "twist tie" implementation, possibly a patent model. My wife found this in a Texas antique shop along with a cool sidewalk prism. The base does not have a pin hole, but does appear to have skirts -- this really does look to be a wood insulator model. Any thoughts? See [id=422552799] for the base view -- shown next to a real twist lock style.