Woofer dust cap repair advice, HELP

I spoke to a speaker manufacturer's customer service department about this issue just last week. They advised that they had done alot of testing on damaged drivers and it was not worth replacing it unless the dent impeded the movement of the cone. In fact, they told me that they had a speaker in their listening room damaged the way yours was when an elementary school class had come for a factory tour, and they had allowed it to remain in their room as is. They also advised that people frequently make matters worse when they use tape to try and fix the dent. Keep the grille cover on so you don't have to be reminded of the dent.