I've pretty much finished up the 1790s open robe. No final pictures yet, as I didn't have light for taking them. But here's a look at the back:
Pleating the skirt to the right width:
I marked how wide the pleats should be on my ironing board with a washable marker. Then I held the fabric up to that and pinned the pleats down:
After I attached the skirt with a backstitch, I felled the seam over itself with whip stitches:
Finally, the belt. It's a couple inches wide, backed with linen.