Richard, I think Doug was referring to the edge grinding as it reveals the place where a sprue (also called a gate) was removed from the piece during manufacture. Side gating is usual on more modern pieces, but my no.7 Erie griddle was made ca.1885 and was gated on the bottom, but not in the middle of the bottom. You can see a thickening of part of the smoke ring which reveals the place where the sprue was attached to the pattern. (Sorry I can't do pictures here--don't know if my verbal description is understandable. :-() The handle style of your griddle is definitely nineteenth century. I think it's a really neat piece, but I like oddities, so... By the way, I use my no.7 griddle to reheat small servings of food, such as a piece of pizza--with very low heat! The rest of the time it hangs where I can see it frequently in the kitchen--it's my oldest user piece.