The letters were no indicator of pattern revision, simply a means of identification among a particular set of patterns in use. For example, a size #6 Griswold skillet has a pattern number of 699 while a #7 is pattern 701 and a #8 is pattern 704.
How do you date a cast iron skillet?
5:3528:47Identifying Old Cast Iron Pans - YouTubeYouTubeStart of suggested clipEnd of suggested clipSuggested clip · 53 secondsWe can use this as a marker for dating the age of a pan if your pan has a stamp saying made in USAMoreWe can use this as a marker for dating the age of a pan if your pan has a stamp saying made in USA you can guarantee. It was made after the Year 1960. And if it doesnt have a made in USA stamp.