Replacement Rib for Riveted Jon

I have a 1991 Lowe 1648MT riveted jon boat. It is a modified vee with 20" transom. I am removing the bench seats (accounting for the lost floatation foam- don't worry), and need to add ribs to maintain structural integrity. I can build some out of aluminum but I think it would look better if I could source a couple more factory ribs to go in there place. Is is possible to purchase ribs from a Lowe dealer, from the factory, or at all?

I'd like to know that myself!

If you can get dimensions on the existing one I can duplicate it. I have plans to do this to my boat just simply to add strength.