Those are seen also in a #11, and both with and without a pouring lip. Not much is known other than they are considered to be from the mid 1800s. The rim around the top would almost tend to imply that a lid was used with them, or that they themselves could be used as a lid for another vessel, in the way later double skillets were, but cast skillet lids were not typical of that era. The ones I have seen, being gatemarked with no heat ring, look like they would be a bit wobbly, but the tops and insides appear to be fine, smooth castings.