Diagram

For my own benefit (if I try to do this again) I sketched up a diagram of how I'm constructing the top.  Here I've tried to indicate where I've made openings (generally involves turning the seam allowance twice and topstitching) and channels for cording, with color-coded cords to indicate how they will go.  I have hand-worked eyelets on top and machine-sewn buttonholes on the inside of the garment, right below.  I expect I will want to draw the shoulders really tightly, so the cord for that will go up from the sleeve opening to the neckline, loop through the lower (inside) eyelets, and then come back out where they can be tied at the shoulder.  The neckline cord will come out at the upper eyelets and be tied there, probably dangling to the back.  If I don't like that, I can always thread on some beads and then send them back inside.

I want to cut the bottom edge to be curved, but am anxious about hemming that curve.  I have almost no spare material, either.  I guess that's a good thing?  Very ancient world of me.  I'll try to do it on one of my small scraps and then if I go for it, there will be some crossing of fingers.