Although I have no idea what type of response you might receive, you might want to join the Georgia Tandem Club's mailing list (aka, PEACHES, an Atlanta-based group) and post your solicitation to the list readers.

http://sports.dir.groups.yahoo.com/g...sec=dir&slk=13

The Southern Bicycle League also has an on-line forum that could yield a few readers with tandems that are gathering dust

http://www.bikesbl.org/