My approach is to buy a Trib JB2, swap the neck with the Trib L2K and then sell the wide-necked Trib JB2. I'm on my 3rd skinny necked Trib L2K made this way (I don't have 3, I only have the latest)
Why not take the existing neck to a luthier and have them narrow the taper from the butt to the nut?