Towing with a 31' Class C, frame questions

I was mistaken, it is an L shaped bracket that runs along the side and the bottom and extends roughly 1 foot on either side of where the extension is welded to the main part of the frame. On the side there are six slots where it goes to the main frame where it is welded as well as a bunch of welds along the top part of that piece of iron. It is not welded on the bottom at all. Despite being a 31 foot RV, my extensions are only 4 feet from the main frame it's self. The brace that goes across is roughly a foot and a half from the tow hitch and is just welded to the top of the frame in the bottom of the frame going across. If I knew what a stock extension from the factory look like I could tell if these were added on as pricing for part of the extension package. It is a good set up however not if it is supposed to be factory LOL