My latest find is this CD 607.7, a very thick, solid, and heavy piece of glass, almost like a solid pour type of insulator, if that's the right word. Interestingly, the entry/bottom diameter of the pin hole is narrower than the threaded portion, which is wider. Is this a result or a practical necessity of the mounting technique, which often used cement glue to secure the metal hook? Regardless, it's an interesting addition to the collection.