Dated c. 1730
Kept at the Museum of Musical Instruments, Brussels.
"German baroque" design;
This instrument has only one diatonic row of strings, but some strings are fitted with mechanical semitone fretting devices. and buzzing bray pins on each of its strings to make a nasal, growling tone.
Info taken from the website of German harpmaker Claus Hüttel, who offers a beautiful replica of this instrument.