Well, you could call the phone number from the FAQs at either of the above linked page and ask. I don't see any cut-off dates but vaguely remember reading something in the fine print somewhere when I returned my iBook battery, but I'm afraid that part of my brain has since gone dormant...or quite possibly died completely... 😉
One thing, though, if the recall is still valid: If you find a used PowerBook, get the serial number on both machine and battery and run them through the checker on the support pages to see if it's already been used before making the final transaction.
Sorry I couldn't help more... 😱