Great news ! Good to hear, as I also cringe when a collection meets a dumpster. Best to you,
I am also trying to find a home for a National Geographics collection - I don't necessarily need to receive any money for them, but want to avoid putting them all into a paper recycling bin or, worst of all, a landfill. Options I am considering, which may be useful for you as well, are 1) Craig's List for your county, or geographic area - section: Collectibles, or 2) freecycle.org - this is a huge online volunteer-run organization, organized on a county basis, where members can post items that they want to offer, or items they want to receive. All transactions are local and no money is exchanged. Hope this is helpful.