I've worked on the sleeves too. The first thing I did was the wrist tabs. I don't want to put a button or opening at the wrists cause I am too lazy to try and find two buttons that might match the dress, so I took my wrist measurement and rounded it up to 8 inches - which still fits over my fist so I can still easily slip it on. I had determined that I would make all the tabs one inch wide, and then the vertical trim on the lower sleeves would be spaced one inch at the bottom and tapered evenly upwards to best give the appearance of the trim in the portrait. The tabs are made from 3 inch squares of the linen sewed into tubes with a half inch seam, turned inside out, pressed, trimmed along both edges and then folded in half. I basted eight together for each wrist. The finished string of tabs turned out to be a bit more then 8 inches (grr) but I think I should be able to ease them into the wrist opening without too much difficulty.
The rest of thw sleeves will be composed of three parts, the lower sleeve, the upper sleeve and the lining. To get the proportions for the upper part of the sleeve, I took what would have been the upper part of my regular sleeve pattern and roughly multiplied all its outside measurements by two. In the portrait it is difficult to determine if there are more rows of trim on the upper sleeve than there are on the lower sleeve. In order to make it easy on myself I decided to make it the same number. As I mentioned before, on the lower sleeve, the trim starts off at the wrist being spaced one inch apart and tapered upward. I took the resulting spacing measurement at the top of the lower sleeve and also multiplied that by two to get the spacing measurement for the trim on the upper sleeve. Once I'm ready to gather the two parts together, matching up the trim should be pretty easy and result in a fairly even gather...I hope.