I replaced my doorknob locks and deadbolts when moving into my new house. I have the original locks still, but don't know what to do with them. It seems unlikely that anyone would want to use them, especially as part of a private sale or exchange as they wouldn't be able to trust that I don't have a copy of the key. Similarly, I wouldn't expect a donation center like Goodwill to accept them either. However, they're still useful locks and seem like something too valuable to simply discard.
What is typically done with the previous locks after replacing them?