I am not sure it shows well in these photos, but the dress now has an additional ten meters or so of hemline under there. I am very glad to have that taken care of. Even with my serger going over a previously serged seam, sewing three layers of organza together was a pain. The fabric was slippery and would drop pins and slip apart and slip out of under the presser foot, and when it was all done I had four places where the new layer had not been sewn to the dress and needed to be redone. But it is all together now.
This operation does not seem to have done anything weird to the length of the overskirt relative to the underskirt, thank goodness. No additional hemming is required. Now onto the stoning!