I have a model 5 Zimmerman 'harp (with shifters) in it's original case from about 1900. I have played it onstage a couple of times, but not for several years. It needs some moderate tweaking now to avoid warping under stress.

Bought it from an antique store that sold mostly furniture. This case was laying on a dresser in the back room. I asked the owner about 'that odd instrument' and he said "That's a zither." I asked him what he wanted for his zither, knowing full well what it actually was. "I know what I've got in it," he said, "and I gotta have $17 for it." I hemmed & hawed and finally, with a straight face, allowed as how I'd part with $17. Grabbed it and ran....

(I managed to work out how to hold it Maybelle Carter style and still use the shifters.)