Okryugeum is a newly developed (around the 1970s) string instrument from North Korea. It is said that you can play the range of a Gayageum zither, a Haegeum fiddle and a piano with it. It has 33 strings, 7 pedals and is played with the fingers while sitting. There are some YouTube videos where this instrument is played by great players, nice sound. Unfortunately I couldn't find any more detailed blueprints for the Mechanismuis, and I'm not sure whether Okryugeum is the correct translation. If you know more details or resources please leave a comment.
A very interesting and beautiful instrument.