To make a fingerboard I cut the wedge first from a 2" X 2" block of ebony a foot long. You can figure out how high each end should be by using some geometry and a calculator. It comes out to about 8 mm at the top and about 11.5 mm at the bottom. That is with a 5.5 mm edge, and a 42 mm radius, and a little extra. I cut it wide of the line and plane both sides flat; with my big jointer plane. Then I cut the edges; that is straightforward enough; and plane them straight.
The only step you need to carve the top is a pencil line on the sides 5-5.5 mm up from the bottom. Hold the blank in your left hand, and with your right hand start planing off big slivers of wood off with the scraper. Hold the scraper at an angle to the blank, and move it generally in a straight line, concentrating on getting it to the scribed line. Ever once in a while check with your fingers to see if the top curve seems right, and that there are no high spots. If there are smooth them out with your angled scraper.
Use a straight edge to see if the middle has some undercut in it, a little more on the bass side. I have to be sure the ends aren't high or low; I've managed to get them both ways, so now I leave the ends long, and saw it to length when it is roughed close to size.
In an hour you will be done.
The blank is now still a blank. I won't finish it until I can work out the projection. That way if I have to keep it thick I can, and if it can go thinner, or needs to be moved around some I have a mm or so leeway on each end for tipping. That is the time you can work on getting the relief just right, the edges even, and that sort of thing.
Try a scraper, it is easy.
