What is more intriguing is the jack (or tangent?) mechanism and
stringing system. Each course of strings serves for two notes in
different octaves due to the multiple bridges. And there are those
curious little dots on / below each length of string.
The arrangement with diagonal bridges and holes in the soundboard
looks very over-engineered for a supposed medieval instrument.
The use of each string for more than one note with multiple bridges
also happens in this 'dulce melos' :
or that of Jack Peters, which both look much more like historical clavichords.