Body cut and set aside, I started on a jig to manually sand a compound radius to the fret board.
After a couple 3D concept drawings, i started to build a test jig.
I set my start and end radii as 10"-to-12", 10"-to-14" and 10"-to-16". Next, I extended those end radii to 4", 8", 12" and 16" (only for nut side in case anyone wants to use it for a 12 string build) from body and nut ends of the board.Then I started building my rough 3D model of what the jig would look like for my 10"-14" fretboard. But as you can guess the jigs for 10-12 & 10-16 boards would be similar.
As you can see, the jig is composed of one base, one moveable top plate and two end pieces at correct radii for their distance to the nut and the body end.
The way I saw myself using this jig is with a long granite threshold or a quarts poly counter top off cut that has sticky sand paper glued to it. The sanding "plane" would ride on the end boards.
The reason I went with multiple offsets from the ends, especially at the nut is so that the jig can accommodate not only fretboard blanks, but also 1-piece neck blanks. I believe 8" from the nut can accommodate most headstocks, but I included 10" and 12" offsets to be on the safe side.
I believe the most important two things about the use of this jig are:
1. Paying great attention to the centerline when attaching the blank to the plate,
2. Placing the nut at exact distance from the outside edge of nut side offset radius board (4" for 4" offset board, 8" for the 8" offset board) so that nut starts at the correct radius, which is 10" for this case.
I used 3/4" MDF for the jig.
Here's the cut a line in pencil so twine doesn't move trick
And this is the draw a radius on MDF trick
which is followed by, "Look Ma! Two separate radiused end plates" trick
Here's the jig assembled.