Willard,
Now I read that the Griswold trademark was first used in 1910. Don't know yet if that is accurate but, if so, would date your griddle later to the c.1910 to 1916 period or even later. There will never be a way to get very close to production dates on many pieces especially ones of lower production where Griswold may have used old style patterns past the time they switched common items to a later style.
Steve
