Selling, donating or giving away a good pair of vintage speakers

I have a pair of Koss CM1030 speakers, which I bought 40+years ago. They are still in fairly good shape but I have not used them since I replaced them for a pair of Magico A3 speakers. I have kept them stored in my office, but I can no longer do so. I hate for them to end up in a dump and destroyed.

Can someone advise me on what I should do to get rid of them?  Should I donate them, give them up for free, sell them and how? I live in the San Francisco Bay Area.

Your always expert advice is much appreciated.