My hope as well. Want to change the oil a bunch of times, get more crud out. At the moment it has Rotella T4 15w-40 from the initial change. When the weather gets warmer the oil pan goes out and gets a good cleaning, valve seals and valve clearance adjust. The list is long, transmission oil, oil seeping here and there, hydraulics... Little by little I'll restore functionality first, then we'll see about the looks.You are doing maintenance that was neglected. Its not unusual with tractors to find them in that condition. Taking care of it you may get some good service out of it. Your compression in that one cylinder won't kill anything. Maybe you can get some compression back after some use. Detergent oil helps do that.
I know you are in a cold climate but I would use a heavier viscosity oil. You could install a block heater in a freeze plug. Plugging it in the night before a big snow makes starting in the morning so much easier on the engine
With work and family I have very limited time to work on the tractor but I sure like it whenever possible.