i have 2 super stuck machines, too. Mizkaki has recommended Kroil oil like you would use oil, careful of the paint and heat. Turn it every direction and turn the hand wheel. On mine the bottom moves freely for reverse and free motion. We are thinking the stuck part is the needle bar. I took apart the pressure bar - it had some kind of bad dried up oil in there. Once cleaned it works fine. I assume the needle bar has the same. I haven't found a local source of Kroil yet. It is on my to do list. I have two machines stuck. Mizkaki says when they are like that it is usually the needle bar.