Farmallmaniac

I didn't know if you wanted this all at once, or a little at a time. Do you have the head off the engine?

If you have the head off the engine remove the ridge from the top of the cylinders with a ridge reamer. Then using first sandpaper, and second a deglazing hone in a drill remove rust from the cylinders, vacuum the powdered rust out. This is so that while you are working on loosening the pistons you won't be working against any extra rust. Then you can fill the cylinders with a few cups of penetrating oil in each cylinder and let it soak, and pound on each one a few times to see if they move. You might also have to sand rust from the cylinders from below the pistons. This will be a gradual proess, and can take days of soaking and hammering. Use a piece of wood on the piston and hammer on the wood to get the pistons moving. It might even help the penetrating oil to soak through better if you drain the water from the water jacket and fill the water jacket with boiling water while you are pounding. This will cause the cylinders to expand for a while and give more room for the penetrating oil to flow through, and will give more room for the rust that is between the pistons and cylinders to be able to roll and slide. If you are in freezing weather you will have to remove the water when you are done so it doesn't freeze.