This will be a dreadnought size, typical martin style back bracing...still OK?
What do you think of the Aesthetics, with the wings?
It is not quartersawn and I wouldn't use it. For me, it has to be quartersawn or it doesn't go into a guitar. From what I've seen for sale I guess I'm not in the majority, but I want an instrument to be stable and since I can't control where it may end up, I give it the best chance at survival (and less cost in repairs for future owners) by making sure it's cut so it has the least movement with changes in humidity.
If that's your only option, I'd agree that you'd need to brace and assemble it when it's dry (under 40%RH, but it depends on where it will live) and you might get away with it.
Thanks for your comments.
I have joined the book matched back sections and just completed the bracing, at about 36 percent humidity.Everything seems fine. It will have an unique look.
I have a very old carved Gibson A mandolin and just noticed it too has a figured mahogany back, under the dark stain, which has held up well.
Actually the mandolin is more likely a maple or birch back, I don't think mahogany was used much on the old Gibson A mandolins.
Quarter sawn is nice but not necessary. As long as you are aware of what you are working with and brace it properly you should have no problem. Just remember that the wood will move differently slab as opposed to quartered and make allowances for that.
It appears to me that you have some variation in the way the end grain is oriented and you need to perhaps add one more small brace in the lower bout to help stabalise that part of it.
Other than that, build and learn, post pics of the project and lets us know how it turns out. We are all interested in learning from others here.