The sleeves
As I have written when planning the gown:
…The paned sleeves are obviously attached to the puffed sleeves of the bodice. In the picture, when closely looking at them, I found that they have some kind of pattern in them. It seems as if they were perhaps made of cut velvet. I have a black silk brocade with a similar, blue pattern which I will use for those sleeves.
This is the brocade I have in mind (right side):
Looks great, doesn’t it?
(the colors are a little dark in this picture. In person, it’s really black with a cobalt blue pattern)
I started by cutting the paned sleeves from Margo’s pattern in that brocade (though I cut them slightly larger than the pattern, as they are fairly wide in the painting) plus some dark blue taffeta, of which I had some remnants from a former sewing project, for lining.
I’ve then sewn those strips of fabric together and attached them to each other in some places which are regularly spaced. Additionally, I slashed in some regularly spaced holes on the outside, to get more holes from which I can pull my chemise sleeves 
I’ve hand sewn those holes with tiny stitches to the lining; each hole got an approx. 5mm seam allowance of both fabric and lining, which was then turned and stitched down, so that I have neat edges around those ‘holes’.
Here’s the first test fitting of one of those sleeves, still without the wristbands (over a modern blouse, so… don’t expect too much )
…well, I think I like them
Next is the skirt.
