Until I read the e-Bay description I was confused by the Magnetic one side only idea. That did not fit with my idea of magnets.
As for the turning, I like the idea better than a pin-cushion and I see nothing wrong with that shape at all. So post more if you improve on it.
Yep, my wife sews, and does a little quilting occasionally so I guess I'd better put one on my 'to make' list.