I had some time today, so I worked the staves down with a portable electric plane, a drawknife, and sander.
As I said before I cut the staves thick, if you have more precise equipment you can cut the initial staves a lot thinner and save time, and wood.
Although certainly not a traditional approach with the tools, I found the portable planer worked very well, I have worked the ribs down to 0.150ths or 3-4 mm so I can finish everything off with a steel scraper and sand to finish. As you can see I set up a make shift work table, C-clamped on end of the rib, then started planing in the middle , planing toward the end directly over the work bench, this stablized end help prevent tear out on the end.
As you can see in the photo if you start the planer and let it get up to full speed, then come down on the wood, this will start your cut nicely.
The thicker ribs I started planing at 1.2mm per pass, you can adjust the planer from 0.5mm to 2.0mm,
1.2mm is the most I planed off at one time.