Karen, the design(s)/patterns seemed to have been constantly changing, (lettering,positions of the lettering, logo(Slant, Large Block, Small Block, EPU vs. ERIE, and on, and on...) The Pattern Numbers with Griswold remained more consistent, but sometimes would vary
.
The real eye opener when I started, was when I received my 'books'... Blue Book, Red Book, and Muffin Pan Books. WOW... was that ever an eye opener, looking at just the various marking changes overtime, on just the skillets! And then factor in the other multitudes of pieces.... groan.
That was when I groaned and muttered... what HAVE I GOTTEN myself into??? ;D ;D 8-) ::)
And then there is Wagner......... :o :o. And Lodge, and Favorite, and......
And the Variations of each type of the Griswold muffin pans. yikes.
Absolutely not as simple as it first appears, this 'Cast Iron Collectin' thing" :D