As far as I know, all windshield frames from 1981-86 had the single rib just above the weather stripping. It served two purposes, to give it strength and provided a drip edge to help keep water from being pushed into the weather stripping while driving. Aftermarket windshield frames from Crown have the two ribs that are like the YJ versions from the factory.
MD Juan Company, who make the Repli-tub, also make a windshield frame but I was never able to locate one from a dealer. It seems they are only available when you purchase an entire Repli-tub assembly that includes the windshield frame, front fenders and hood, along with the tub. I gave Rommel from MD Juan my windshield frame so they could improve their product for our Jeep CJ's.