I built this unusual instrument based on a 100-year-old mandolinetto that was kindly sent to me on loan so I could take measurements and make drawings.
For the story of how I came to discover this old-style instrument and to see photos of the original please see the linked page Inspiration for Mandolinetto
I made a few concessions to modern times in building this. I added a carbon-fiber reinforcement rod in the neck. I also changed the headstock design to allow use of modern tuning machines and angled the neck back so I could use a height-adjustable bridge.