Here is the underlining (sorry it's basted together and has pins I used during the fitting.) I used it for the final fitting garment. It's lined with fusible interfacing to give it body. I had to take in in about 1" on the lower front and back seams. I used Wildginger Pattern Software to draft the pattern. Since it's underlined with the interfacing, I can use it to cut out the sequin top.
The upper back didn't have a hook and eye, hence the separation. When I held it together it was just fine. I'm going to also add boning. The layers of organza ruffles will be added to the skirt and I'll add some horsehair braid to the hem so the ruffles set out a bit.
Don't know why the color of the dress came out like it did, but here is the actual fabric. The underlining is actually the same color.