Oh man, what a bummer Chris.
Don't know if this gives you hope or not, but bites finally settle about a year of age. Changes can occur up until that time frame. (Lots of recent discussion on this topic on Showdogs-L, an international forum for those who show - hence the name <G>).
Not sure where you'd find balls that small and one that small I'll have to admit to worrying that he could swallow it. YIKES! Did you by chance come across any of the small Kongs? Some of the puppy ones or those for Toy breeds are pretty tiny in diameter on the smaller end and might be the closest in size to what was recommended. A little stuffing and maybe a good incentive to get him to work his teeth in the recommended way.
Good luck!
Debbie