Initials E.S. inside a Rectangle

by Sheryl

I have a ring stamped 14k 585 - clear enough. Then turn it upside down and there's another stamp, apparently a hallmark - the initials E.S. inside a rectangle. The initials look a lot like that for Ehrlich & Sinnock here, except here there is no rectangle:

http://chicagosilver.com/jmarks5.htm

Still, Ehrlich & Sinnock made jewelry from 1909 to 1931 (deco), and the style of this does look deco. Do you think it's Ehrlich & Sinnock?