Dwayne,
Once you get before the standard early Griswold and Wagner style skillets anything seems to be normal. So the unusual rim your pan has is not anything unusual. Nice looking pan with those little big lips. I don't know if I have one like it but it does look familiar but not common unless I am not seeing the details correctly. Yes, the number on the pan (some pans) corresponds to what size stove lid the pan is used on. That would be mostly sizes 7-9 as they were the most common size of stoves. I think the other sizes are just relative to the 7-9 numbers. This type of numbering lasted until c.1960's when the remaining foundries gradually changed to skillets sized in "inches".
Steve
