Just a quick note, and you may wish to verify...Purpleheart wood , as I seen to recall, is rather toxic. I should say that the dust from sanding is toxic, and can cause all kinds of pulmonary problems. When I had a Bookstore, there was a fellow that made many awsome woodcraft items for me, several contained Purpleheart. I asked about making a fretboard out of it. It was then that i found out about the "downside" of using this wood. I'm not yelling "stop", I just want you to be aware of the potential problems of using the wood, and to be safe when sanding. It's a beautiful wood, and lends a unique quality to the appearance of an instument. I encourage you to look it up, as my information may be a little old and/or faulty, But the fellow was an experienced craftsman, and better safe than anything.
Build On!!!