Aaaaand, the collar.
This is just draped out of duck cloth with a piece of jewelry wire in the back seam. I am thinking of two options, there's this fusible stiff pellon stuff which I'm going to make the mock-up with, and horsehair canvas with wire in the seams. I would have draped the sleeves while I was at it, but I don't have any netting on hand. I'm going to make a full undersleeve (though seamed at the elbow and plain fabric underneath) and make a poofy under-sleeve out of netting to support the velvet oversleeve.