Raymond, I' ve made a few selfbows, but I' m no expert. Certainly not when it comes to making a recurve selfbow. But I don' t think the basic rule on bow length would change... double your draw length and add 10-20% for the finished bow length. For a recurve, I' d say that would do for the blanked out stave. Then you can boil the ends and bend them over a form to recurve them.

I' ve been wanting to try my hand at making a recurved selfbow, but just haven' t been able to summon the courage to try it yet. I' d bet it presents some challenges when it comes to tillering.