This is an osage static recurve selfbow I built a few years ago. This bow was built and shooting 2 months off the stump and after a few hundred shots it developed a hinge and chrysals. I am sure this happened because it was not properly seasoned.
After about year or so I ground down the belly below the frets and added a thin(1/8"on thick end) tapered Argentine osage belly slat with Urac. When first built the bow pulled 47#@26" and after adding the belly slats and re-tillering she pulls 55#@26" and sends a 650gr cane or sourwood shoot arrow with authority.
It really doesn't take much wood on the belly to increase the draw weight on a bow. I think the act of gluing on the other slat and the glue line itself adds to that weight too.
These pics are from before I added the osage slats but it is the same bow...
You can see in this pic the Argentine osage that was added to the belly. Note the different color...
and a braced pic of the repaired bow...