Dear Mr. Waring,  "Autoharp" is a registered trademark owned by the
Oscar Schmidt Company, their brand of the chorded zither.  It sounds
like you have a smaller, generic version.  For more details see
http://www.oscarschmidt.com/

You might also find this web site of the Country Music Hall of Fame
helpful as it has a little history about the instrument:
http://www.halloffame.org/hist/instruments.html

I have had a few Autoharps over the years and love to play.  Along with
being strummed for chords, they can be "picked" to be played as a solo
instrument -- something I learned to do after seeing Bryan Bowers in
concert several years ago.  Visit his web site at  http://bryanbowers.com/

You can also hear samples of his music at www.amazon.com

Sincerely,
Pamela Sanders
Sparta, TN, USA