Minimalistic leaf wave relief

I would like to reshape the polygon mesh that I have shown in the picture as well as possible with Grasshopper. Basically, I’ve already used an old script to create the waves using 2 curves, but I can’t get any further with the inner curves.

My goal would be to create a solid with 2 curves and a point defining the midpoint of the inner curves, which I can then take off the plate. (18.8 KB)
leaf-relief-v0.2.3dm (54.5 KB)