So I ended up using the pattern on the left (Butterick 7304) for the bodice, since it had a dropped waist, and the pattern on the right (Butterick 6937) for the neckline. I just kinda did the back neckline by hand. I am really happy with how it turned out! I had to size down the bodice pattern, which is what took so long. I also ended up doing a sway-back adjustment. I need to start checking for that on all my clothing. Rgh.
So here is the muslin. I am going to look for fabric today to see which color would be best. Although I am thinking about the color of the background of the picture. We shall see.