At Urban Ore someone has thrown away a bunch of big gourds that they had started to make thumb pianos out of. There were gourds with just one side cut off, and ones that also had a 3/4" wooden face glued onto them, with a hole in it and a wooden bar across the face like a guitar has to hold the ends of the strings. Plenty good-looking. People were snapping them up -- some were planning to make a birdhouse out of theirs, and a woman was going to make masks out of hers, although she had ones with wooden faces on them.
You could easily use one as the body of a ukelele or some kind of mandolin. I did something like that one time for a "box show" here in Marin where everyone starts with the same size box and the artists' work is auctioned off. I wish I'd bought mine -- I used a 1/8" aluminum printing plate with fruit-label images on it for the face, the box for the body, and a neck from a real uke, strung with real strings. You could play it!