Sheryl I noticed that None of the maker's marks on page you sent through in the link have anything behind them. The absence of the rectangle on that page, is therefore no cause for concern here.
I did a quick check on the initials and there are a couple of companies with the initials E.S on the other side of the pond, (also in a rectangle) however as the ring is marked 14 K , the "K" usually indicates it's been made in the US.
I think you are probably right, especially if the ring is keeping with the art deco style for which Ehrlich & Sinnock were known for . From the information provided there is no reason to believe otherwise. You really are getting dangerous now that you know how to use a jewelers loupe ;-)
