Asked my zither-collecting friend about Bill's question at the top of this thread, and he said:
"...No idea as to worth, however, there were numerous zither like instruments made here during the last half of the 19th century and sold door to door in rural america. Usually the salesman brought his daughter who could play it with ease. There was a wide variety in the configurations of the instrument including how many strings, the tuning, the way it was played. Some were called Zither but often they had invented names...
...This, however, sounds like a true zither since the company is international. Although you never know. You have to look at the string configuaration and see how it is tuned to tell if it is a true zither...the upper portion was a regular chromatic scale..."
Hope that helps, Bill. Is the daughter still in the original packaging?

Bark Woof