Chambure Vihuela measurements

[Dr. Henner Kahlert]

I am building my second Chambure Vihuela according to a set of plans by the Musée de la Musique, Paris. After a very long time looking for a method to bend the fluted ribs of the back I found this article by Richard Coleman, Sixteenth Century Rib Bending:

https://www.fomrhi.org/uploads/bulletins/Fomrhi-103.pdf

p. 1753 whose method I aplied. I used pear wood, which should behave best according to Coleman. Now I tried experimentally to bend one rib in1,2 mm maple, which stayed stable after bending. I hope the other ribs will do just as well.

I was not very happy with the sound  of the first instrument with pear ribs and sides (see picture of the back). Perhaps I should not oly use maple ribs and sides but alter the measures of the soundboard and soundboard bars (only two bars over and under the soundhole). The thicknessing of the soundboard in the plans appears rather irregular, from 1,9 – 2,3 mm at the edges up to 3,6 mm al the bass side near the bridge

Now my questions: I would appreciate very much if someone would recommend me the ideal measurements/thicknessing of the soundboard and soundboard bars