It is hard to get very good results doing it any other way than this:
Leo Buendias build thread at the AGF:
http://www.acousticguitarforum.com/foru ... p?t=400216
The trick is you need to have your contours perfectly shaped before routing the top and back binding ledge. Once you do that, you go back and cut out the florentine points. I use a gramil, saw, and chisel. I then install the top and back binding including the top and back florentine sections. You then chisel out the miter from the binding points and then you add the side florentine binding/purlfing pieces. I also do the same thing at the tail. I route my tail inlay channel and the put an easy to cut out wood like spanish cedar. I just chisel it out after I've bound the top and back. I find this much, much easier to get perfect purfling miters this way. The Leo's build thread shows several of these steps and you can see how this process allows one to align everything very easily.
Here's a photo of one of my instruments - each florentine point is fully mitered.
