My model is made with smaller stitches, using quite a fine cotton yarn, so I did add some extra rows in the middle. It's the first time I've tried to make a two-colour spiral pattern and it was in fact very straightforward.
I made a rattle with a plastic "egg" filled with a few plastic beads. I wrapped the "egg" with the stuffing, and then put the stuffing in the foot of an old stocking before putting the whole thing into the crochet ball. Then I finished off the spirals and now I just need to send it off to Alfie.