Indeed. I'm wondering if it ever did work? While the part is called Bobbin Winder Bracket (belt cover), I'm pretty sure the hand wheel wasn't made for a belt. It doesn't look like the hand wheel is shaped to accept a belt. Also it doesn't look like the belt would have a clear path to the motor as the Bobbin Winder Bracket looks to be in the way.
Janey - Neat people never make the exciting discoveries I do.