[QUOTE=SteveH;7371676]The gap is where the take-up arm should be. That screw is the pivot for the take-up arm also.
Definately a needed component.[QUOTE]
Well, yes I can see the usefulness in that.
But if you look at your samples, and this one
http://www.needlebar.org/cm/displayi..._display_media
it looks like there is something sticking out from the gap.