Jesus, I wouldn't even wait. I'd tell them to just hold on to them, sell them, have the buyer send their casts directly to JH Audio, and have JH Audio send them directly to the recipient.
How is it you know you have a loose driver? I'm not questioning you, I'm just curious how you would know, and they wouldn't. It sounds like it should be painfully obvious, and there's no excuse not to recast/recase them.