I have this N.O.S. Illinois Case Co. case and I would like to case a movement that is of the approximate time frame. It is a 16sz. case and I know from the square bow style that it is not a real early style case. Perhaps some of you more knowledgeable collectors can date this style. Thanks for looking.

I can tell you that the Horological Trademark Index says that the Illinois Watch Case Co.

Has Supreme listed as:

Filed July 26, 1923
Used since 1894
Claims: Watch Cases and movements.

As far as when yours was actually made, I can't help with that, but I'm sure others can.

Your case with the crown directly on the case body and in the chrome base metal case would be appropriate for any 16S movement from the 1930's on.

Case pendants became progressively shorter from the teens forward.

Tom