I replaced a rusted keel on an aquarius 23. I had a local machine shop cut a piece of 316L stainless and weld the stop tab and cut a hole for the pivot pin. that cost $700, mostly for the slab of 1/2" stainless. The plasma cutter did quick work and I think the labor was under 2 hrs. The aquarius has a skiff keel that runs the full length of the boat and this is where the pivot pin was located. The original one was a 3/8"bolt. I used a 1" rod of the same stainless. Installing involved cutting a 1" hole through the keel and epoxying the rod in. I ran a piece of 2"x6" aluminum tube from the top of the keel trunk to the deck. Inside this was a tackle setup that was I think 4:1 purchase. It exited through the deck and ran via turning blocks to the cockpit and a cam cleat and winch. The winch was unnecessary as raising wasnt a big deal by hand with the 4:1 purchase. I sailed the boat for 12 years after that modification and it always worked without a hitch. I consider a kick up rudder mandatory with a swing keel. I broke two rudders off before building a kick up stern hung rudder. It was really cool then. I could sail right across sandbars and the bottom would fold up and go right across effortlessly.