It may have "Sidney, Ohio" on the bottom or just "Sidney O." This indicates that the piece was made by Wagner Ware before 1922.
Wagner and Wagner Ware (did you know there was a difference?
) seem to get less respect and I think that's both good and bad.
Check for a Wagner Ware name, along with a Griswold name or a cross inside a circle.
The Griswold company sold to Wagner in the 1950s and all the production of those pieces moved to the Sidney location.
The term "large", however, is more properly applied to the block lettering rather than the diameter. At what points the changes thereafter occured is uncertain.
During its period of production, the small block logo skillets underwent design changes to the handles, resulting in what are known as the early, late, and late grooved handles. The medium block logo or late large TM is believed to have been a planned replacement for the small block logo, but whose development was possibly cut short by the acquisition of Griswold by Wagner Ware. Trademarks varied from as simple as the name of the city of manufacture in plain, block letters, such as the coveted "Erie" pieces produced by Griswold in the late 1800s, to the more elaborately-styled scripts, logos, symbols, and descriptive markings used by Wagner, Griswold, Martin, Favorite, and others up through the 1950s. Favorite Piqua Ware Block FPW Block "The Best To Cook In" FPW Stylized Font FPW Stylized Font "Smiley" Favorite Stoves & Ranges Sunrise Logo Miami Diamond Logo FPW Smiley/Miami Diamond, Dual Logo Puritan (Sears Roebuck) by Favorite 3¼" Diameter, Italicized Lettering aka "Slant" Logo (1906-1912¹, 1909-29², 1939-44³) 3¼" Diameter, Block Lettering aka Large Block Logo (1920-1940)⁴ 1⅞" Diameter, Block Lettering aka Small Block Logo (1939-1957)⁵ 2¼"-2½" Diameter, Block Lettering aka Medium Block Logo or Late Large TM (1955-1957)⁶ Griswold Slant "No Erie" (1909-1920) Victor (1900-1910) Victor/Griswold Mfg. aka Fully-Marked Victor (1920-1935) Good Health (1920s-1930s) Best Made S. It is also seen in slightly varying diameters on pieces of the same pattern number, leading some to differentiate smaller instances as being a "medium logo". Manufacturers ├ Canadian Manufacturers ├ Trademarks & Logos ├ Numbers & Letters ├ Economy Brands ├ Store Brands ├ Damage & Defects ├ Reproductions/Counterfeits ├ Ghost Marks ├ Identifying No-Name Iron ├ Non-Collectible Cast Iron ├ Collecting Strategies ├ Iron Hunting ├ Buying Tips └ Selling Tips ├ Cast Iron Restoration ├ Aluminum Restoration ├ Glossary of Terms ├ Patent Database ├ Foundry Database ├ CICN Re-Mastered ├ Sand Mold Casting ├ Cast Iron Finishing ├ Factory Automation ├ Informational Links └ Videos Listed here are the trademarks or logos of the major U. cast iron hollow ware-producing foundries of the late 19th and early to mid-20th centuries. (Sears Roebuck) (1920s) Puritan (Sears Roebuck) (1920s-1930s) Merit (Sears Roebuck) (1920s-1940s) The large block logo is seen shrunken to accommodate size restrictions such as on small skillets or the undersides of lids.A Wagner Ware #8 skillet like the one pictured above can be easily purchased for less than twenty five dollars.Mine will cook omelets better than some Teflon-coated sissy pan yet they do seem a bit under appreciated.Information dating it to as early as 1955 has been found.