Hand sewing the panels together took a total of about 10 hours, here is the first (and easiest one) done, before I tackled the scalloping at the bottom.
When all that was done, I traced the pattern out again onto the lining fabric, a very soft cotton, and then sewed them together right sides facing and added the graded wadding. This part took a lot longer than I thought it would, there was a lot of smoothing out to be done.
When I'd turned it right way out, it was time to pin. I started by following the ones I had traced out (very faintly) on the liner, but for some reason it wasn't really working. So after all the time I had spent working out the feather patterns, I pretty much scrapped it all. The version I ended up with was just made from careful pinning and re-pinning until it looked right.
After I had quilted it (which was a fairly quick process compared to the rest of it, due to the wide spacing of the feathers) I added on the waistband, the very last little bit. I had a battle with what fabric to use, the plan was to use the darkest skirt silk, but when I ironed it onto the waistband interfacing it changed the colour to an icky grey. So in the end I used the pale grey silk of the corset. I pleated the wings in with small pleats and hand stitched the waistband...twice. Either I measured wrong or the fabric shuffled as I sewed, because waistband attempt one ended up 4" too large.