Sounds like by trying to turn it over you have jammed it up with the rust Tyler was refering to.
When an engine sits like that, normally, the best thing you could possibly do would be to seperate the block from the tranny, drop the oil pan, rod bolts, main bolts, pull the head off, drop the crank out, with the head off you can now push the pistons out the bottom of the block (dont forget oil squirters and oil pump).
Then you can clean the rust out of the cylinders with a stone or ball hone.
What forcing the pistons to move up has likely done is wedged rust with the rings and its scoring the cylinder walls likely to a point where you're unable to move them anymore.
I fear you're going to see some hefty marring on the cylinder walls (as i did with my old engine) now when you take the head off and move the pistons back down.
Remember, you can also always move the pistons by putting the car in gear and forcing the wheels to turn. In 5th gear, you should be able to apply a lot of torque to the crank from having 1 wheel off the ground - or just rolling the vehicle forwards or backwards.
Unfortunately, you may have been too hopeful with this engine. Had it been an air tight seal, the bores likely would have been fine.
That's something to remember - when parking a car on long term, loosen the cam off so the valves seal the cylinders from the moisture.
Call me a pesimist, but you may need to do a mini rebuild on her to have it run right. No boring, just a hefty hone and re-ring and it'll probably run.