Whatever you do, you won't go wrong. Most guitars are overbraced and they do sound good. I have scalloped almost everything I've made and they have all turned out good. I don't want to snatch your thread but this is my basic approach. Start with something that looks pretty much like yours. Cap the X (or put a piece of linen on it, follow Char's advice about not doing it like Gibson does). Feather the ends of the UTB, X and tone bars to fit into your notches in the lining (again, don't do like Gibson did). I then shape the braces to a peak on the top, more or less like this That would pretty much look like my 1957 plans and would be acceptable for a floppy top or a guitar that was going to see medium strings and lots of hard strumming. If you want to scallop then follow the established shape, just take a big swoop out of the middle of the X and tone bars. The bridge wings sit right over that valley in the X braces - in theory they are imparting energy to the top at those points. One of the things I do with the ends of the braces that will be tucked is lay a piece of scrap wood next to them and swoop down with the chisel to that scrap - I use a cutoff piece of the top. That will make all of the ends a certain height, say 0.110 and if you use that scrap to set the depth of the notch everything will just snap into place. The little finger braces get feathered and are not tucked. Here is that top pretty much finished - I would consider this typical scalloping for a fingerstyle OM sized guitar. This guitar is now a couple of years old, has opened up nicely, has no structural issues and sounds pretty darn good.