Treasures in the attic

When we moved into our new old house we found lots of treasures in the attic. The people who lived here before didn't quite get all of their belongings from the recesses of the attic. The woman who lived here passed away, we are not sure what happened to the man. Their kids sold the house. Once we got up to check out the attic we found old yearbooks, pictures, wedding papers, christening records, bank records, car insurance documents, tax records, an ancient pair of ice skates, military records, war letters from WW2 and an old painting of a child in an elaborate frame. We called the daughter and left messages, we called the son and he said they would get in touch to set up a time to pick it up but never called back, we sent a letter. I guess they just don't want this stuff. I don't know what to do with it. I don't want to throw it out but I don't want to store it forever. Do I return it to the attic? Do I see if the historical society wants any of it? Do I sell it on ebay? It was fun finding treasures I just don't know what to do with them now. I guess they may become part of the history of the house and stick around.