I suspect that Novelty also made some of the Manhattan insulators... this one is somewhat junky glass, nice yellow green, and has a characteristic "circle" up in the pinhole. This is a feature that is connected with the Novelty glassworks, and is often seen in Knowles, Star, and other insulators. This picture tries to show it (hopefully). It appears to be an artifact of the tooling process used to form the threading mandrel. (I have also seen this style in blue glass, so I suspect that Novelty made some blue glass also.)