I have thought of building a sailing barge out of an old fiberglass trihull shaped houseboat.
Get a 36 0r 40 foot one with a bad cabin and engines for nothing and gut it.
build a cabin similar in shape to escargo or a sailing barge with the sole on the bottom of the hull.
leave 2 feet of hull around the cabin all around for decks except have 4 feet aft. The cabin should stick up about 4 feet from the deck to get headroom and the pilot house should be at the stern to keep the windage aft.
Here is the tricky part, take all the transom off except 2 feet or so in the center . Cut the bottom going forward for 5 feet at the edges of the remaining transom and do the same at the bottom to side chine.
remove all interior
reinforcement and jack the big bottom tabs at the aft end up to deck level and join to deck. join the bottom tab to the sides and build sides for the 2 foot wide rudder skeg<remaining transom>. Big barn door rudder on the back of the remaining transom and a small inboard inside it.
So now you have a scow rear end on this hull and even though the front looks different it will act about the same as a scow front. A couple of lowering masts with a moderate sail rig and you are off.
there will be some lateral resistance due to the straight hull sides and the 3 hull configuration of the bottom, but I would depend on the engine to motorsail into the wind. should do ok, leeboards added if needed.
This boat should actually sail. resist the temptation to put too much superstructure.