I fixed the line of the skirt today. I also figured out how to fix the neckline. Here's what I did.
I pinned where I needed it to fall, front and back. Then I folded the kirtle on that line and drew a straight line from the pinned area to the fold. I sewed a straight line between these points. Turned right side out there is a small seam in the front and back, but the way the gown hangs you really can't notice it.
I'm not completely happy about this but it was either that or having to add material to the neckline and there wasn't any way to do with and still look period.
Trim and hemming left.
London in May
2 weeks ago