Dated 1740
Kept at the Museum of Musical Instruments, Copenhagen.
"German baroque" design;
-- strings
This instrument was made by Johann Rabe; it has two parallel rows of strings, for diatonic and chromatic notes, 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.
Simon Chadwick