So, 16 months later I have a completely hand sewn C18th outfit - the gown alone took 9 months, but that's because I had problems with the sleeves and so put them at the bottom of the sewing pile, which is just as well as they now fit me!
I wont go into massive detail about the sleeves - they're similar to early modern in that they have the seam running along the back of the arm. They are also a little longer (tapering to a point) at the back so it covers the elbow. And they are big enough so that they can be gathered at the shoulders - my gathers measure at 2".
The skirt is made from 3 panels because my silk wasn't that wide. The back panel is the widest and then there are 2 narrow ones for the front. I can't remember the measurements off the top of my head, but if you want to know just ask and I will measure them. They were probably about 40" in length to allow for hems and to fit over my petal pad which makes the bottom bigger! The skirt was hemmed first and then the waist seam was turn over to get the right length. It was then pleated (about .75" pleats) and sewn to the bodice.
After all this, it was time to make the gown look pretty and even more C18th! I made cuffs that are permanant ones from the same silk - often seen on extant gowns. The width was twice the sleeve measurement at the elbow (so 14" x 2 = 28") and 3" at the longest point, tapering to 1" - I added extra for seam allowance. Once these were sewn on I had to make and sew on metres of pinked and pleated 1" wide trim. I eyeballed the pleats for this as my silk is stripey so I used the stripes as measurements. It worked out that around a 4m strip of silk, when pleated, would give me about 60" of trim.
To see the finished outfit and gown please follow this link.