Here are the "ears" being glued and clamped. Only a little bit is needed for the bump by the first machine head, but quite a bit is needed down the other side because the neck is angled so the string paths are straight.
Then the truss rod slot is cut and routed straight. It's a martin-style single action truss, and it'll adjust at the headstock under a little removable cover that I'll make (like a Gibson cover but curved). The aluminum U-section adds a lot of stiffness with these truss rods.
And here's the whole thing waiting for some glue and clamps. Someone wise said that a man can never have enough clamps - this is very true with guitar building. I'd like to add a bit to that and say that not only can you never have enough clamps, but you need variety in your clamps too. I have tons of monster clamps and baby clamps, now I must travel into the city to get more medium clamps!
Then I can cut and route the neck taper, the truss rod plug and route the headstock. It'll have a 42mm nut (1.65") and a 30" Mustang bass last fret width, which I think is 2 1/16". EDIT: 2 3/16"
The scale should be about 30 inches depending on where I put the bridge. No frets = no set scale length!