Found in a 'Downeast' antique shop full of WAY overpriced damaged common insulators. Paid 20$ I had just gotten the book, but couldn't figure out what this one was, and had enough others that I was having better luck with that I set it aside until one day I saw one on eBay. this one has a nice little amber snake by the mold line, and the inner most skirt pulled during manufacture so it sits at an angle.I'm guessin' that's an Elmer ring at top of pin hole, threads are very rounded. 2019 update: Sold her down the river for vacation cash. You might see her if you like rollerskating. I'll miss old wobler with her olive snake... Just kidding.- Enjoy! I got another one.