Unknown U number porcelain signal that I am pretty sure is a Pittsburg piece with writing on it. I have seen a few other Pittsburg pieces with writing on them and it is usually a mirror image where the letters are backwards. The best I can make out is something along the lines of a handwritten "HC ?M" when viewed normally or "W? CH" when viewed in a mirror. It could be "HCH" viewed either way. "34 50" appears to be incuse stamped near the top of the dome. On the dome top is also what appears to be a star with a face in it which is visible under bright light. This could also just be a random pattern in the glaze. I will post multiple pictures for you to come to your own conclusions. There is a pinky nail shallow flake on the upper wire ridge. Irrelevant to me given the scarcity of porcelain insulators with writing on them vs. fingerprints. Price $250 shipped. First email as always. PayPal welcomed. Contact me first for details.