I just did this conversion. The lock washer had three tabs on the outer edge that bend away from the machine when installed properly. Then the shiny stop motion knob screw will hang up on one of the tabs to stop the needle movement when it is unscrewed. I followed the tutorial on a vintage sewing machine blog to get it together so the needle bar doesn't move when I unscrew the stop motion knob. My Franken66 is a combination of parts from a 66-13 that came in a cabinet ($10 from local CL), the spoked handwheel, bobbin winder and faceplate from a Red eye 66 with bad decals ($12 from local GW), and an earlier version of the Chinese handcranks that has metal gears and no decals ($20 on ebay). It sews very nicely, and the handcrank operates smoothly, but I haven't been able to find replacements for the broken hinges on the case, so it has a tendency to fall into the case. I guess I will make a new base for it as the cover won't fit the base with hand crank on it anyway.[ATTACH=CONFIG]593095[/ATTACH]