Here's a couple of quick renders. Some things are sort of subjective, like top and bottom overhangs. This is just a jumping off spot and if I were building, I'd do as Jay suggested and plan on locating pieces via dowels, dados or some means. Many ways to skin the cat.
If one plans on recessing driver flange, I'd think you'd want to thicken the baffle. Didn't draw the extended base, but that's just a matter of adding to one dimension. FWIW, I almost never build without having pertinent pieces (amps, drivers) in hand so I can assess things on the fly or puzzle something out.
