Who made this?

I have tried to include 3 pics of this # 11 skillet but no luck. After checking many sources I have no idea who made it, and will appreciate all help. FYI, this skillet was passed down from my Great grandmother. You will note there is no gate mark, there is a fire ring, but no name or the usual identifying marks. The most unique feature is that the "size" number is on the bottom of handle in highly raised double vertical bars. Wish I could have included a pic.

Here are 2 of the pics.

Appears to be a copy made from a 1st series Erie skillet. If so, markings, which all would have been on the bottom, would have been filled in and the 11 under the handle added, either to the resulting pattern or at the time of mold making. Incised marks wouldn't be feasible to add to a sand mold, but impressions made in the sand result in a raised marking on the iron.

I think in view of family lore this skillet may be 19th century. Could this be correct. The iron is quite thin compared to other items I have.

1st series Erie skillets date to the early 1880s. A copy could date any time around or after that.

http://www.castironcollector.com/erie.php