One day I promise I will read instructions, think things through logically, follow said instructions and come out with the required result! For now, my 'ball' is actually a greater-spotted dodecahedron! It seems to have gone down a treat with my 3 youngest critics, so I'm happy with that!
I unpicked the wonky whipstitching, and whizzed round again (equally as wonky) with 3 strands of embroidery silk, but didn't really pay attention to the ridges I was creating. Hence there was no slack to flatten out the seams when I was done. Ho hum... live and learn!