I had a book which tells how to make a useful basic violin - the body is a triangular-shaped box. There is also an interesting thing called a bowed psaltry, which is a lot of strings stretched over another triangular box. Both these were fairly simple to construct, and serious working instruments. I'm sorry I can't provide more info, but I'm fifteen years and two hundred miles away from the books I read. Re: Appalachian dulcimers - the design can also be simplified to a triangular box with round sound holes, making construction very easy.