That's a mandola body with a long neck, a 21" scale; I've also made mandolins with a mandocello body. It has a finger-rest & tailpiece of my own design. The finger-rest is, in fact, removable but doesn't touch the top or sides - only the fingerboard extension. The tailpiece is bronze that I have cast; I did the original wax model. The fingerboard is raised above the top, like an F-hole model. I made two of these at once. The other one had F-holes & tone bars; this one is X-braced.