Left was the original hinge design.  A single braiding band wrapped just above the hinge provided enough spring tension to close the flower and held it all together.  Worked well, but used a wedge inside to push the flower open.  That made the petals stack up resulting in a flat rose.

Right was the revised design  Now pushing on the extended bit opened all the petals evenly.  Problem was it was over-constrained.  

The hinge on the left was sloppy, and allowed the petal to flex left/right as the flower opened/closed.  I eliminated that flex in the second design, but that turned out to be important.

Opening does not trace a linear path as the curved surfaces engage each other, and the flex allowed the petals to slide over one another without binding.

So I need to cross-breed these two strains and I'll have the flower I need.  That will take more time than I have.