Thanks Geckostar97 -- Wish I could be credited with the design, but an old boy named Jacob Gross made two round-bottom zithers back in the 1860s -- one fretted, and one bowed. And his were based on the earlier fretted zithers of the Moravian settlers in PA.
I may tackle the bowed version next as it's a bit simpler. Right now I'm staining and sanding and staining again the fretted one, trying to get the color at least close to the original...