Just picked up a Wagner curved Logo No.11 skillet, it has the outside heat ring and the reinforced handle pad, The Wagner logo is set in between the heat ring and the center of the skillet, I had to set up a new lye bath to fit it and will post some pics as soon as I can get enough of the crud off to see if there is a Sidney O mark under the Wagner.
I believe it dates from late 1890's to early 1900's, The number 11 is on the bottom and looks hand inscribed.