Looks like you have done some hard thinking on a 457 stylist. My problem is hand wheel hard to turn. Lubricated still no help. Gear in good shape. Everything is turning in the hook assembly but I wonder if some thread is wound up under assembly. Any thoughts. Told a friend I'd could probably fix it for her. Also I was wondering as I don't know the machine but the thumb wheel that you select zig zag or blind stitch turns all the time when I turn hand wheel. Is that normal.