Jerry,
It's NICE crud. Not too thick but thick enough to obscure any markings (I think). I see the "9" plainly so maybe there aren't any more markings. Thinking of bringing the do to convention. It's too pretty and with a nice, smooth buildup of old cooking oils to clean-at least for me. More and more I am liking my pans dirty. But with a nice dirt that makes the pan look very well cared for and used.
Steve