Do an air pressure test. Loosen the adjustment on both valves on cyl. #1, turn the crankshaft so the piston is at the bottom of the stroke, and put air pressure into the cylinder. If there's a major crack or a blown cylinder wall, you'll get a big volume of air escaping from the radiator hose fittings and no pressure buildup. If it pressurizes, the engine might be rebuildable. Either way, I'd consider it to be a "rebuildable core" at best. Sometimes the expensive lessons are the most lasting ones.
Jerry
