Look at this: http://www.larkinam.com/MenComNet/Business/Retail/Larknet/ZithersDoes it look like any of these? Beyond that, I have no other ideas. Also, I don't know anything about these instruments, so beyond maybe helping you identify it by a picture I don't have any more help for you.
Another tip: If you know what country the instrument originated in, you could look through Lark in the Morning's ethnic-origin pages.
Peace-- Keli