Your analysis is spot on! Both engines had been sitting for a very long time in a salt water environment. Heads were pulled and cylinders were ball honed with pistons at BDC and sealed with a rubber plug to prevent abrasive from reaching rings. Cylinders were cleaned with purple cleaner and rinsed. A bearing cap was pulled and showed little wear. Both engines are currently performing flawlessly in St. Augustine, FL. No strange noises, no smoke. Will take your advice and change the oil.