You should known the CPSC is one step away from banning these entirely. The original manufacturer Maxfield and Oberton has stopped making them. Selling them will be illegal and eBay will end your auctions without compensation if you list prohibited items. Further there are law firms all over the country gearing up to sue everybody involved in their manufacture and sale. I dare say the way things are in today's litigious community, even if your balls never end up in the hands of a kid who sustains injury, you very well can be the target of one of these suits.

An LLC or corporation will not likely help you.