Who would take a set of 1986 encyclopedias?

We just moved into a new house in southern Maine and discovered a mint set of 1986 encyclopedia brittanicas packed in boxes in the basement, and it also includes 2 subsets of books. All mint condition. We were surprised to find out no one seems to want them, including the local library and public high school. This is mostly due to the being outdated. Still, we hate to just throw them out - and the local transfer station dump charges for getting rid of big heavy books. Ebay is out of the question since it would cost a small fortune to ship them. We would like to donate them....anyone have any suggestions?