Here is a pic of one for a bass. It appears to be fully adjustable, but can't tell how intonation is set without loosening the strings (which I think would be kind of difficult). It appears to use some sort of metal for height, but I would go with wood. I have some walnut and dogwood laying around which may be hard enough to handle the string tension. But I would think I would need some sort of metal in there to be able to tap it for a screw. I saw another out there for a guitar, but for life of me can't seem to find it again. If I do get this project started, I will post pics with some progression.