The back band is gathered (it was not in the original). I don't know how the original dress was done exactly, but the shoulder strap will be attached only at the seam that connects bodice with skirt.
I think I figured a way to do the bust area without misshaping the breasts (a concern that was duly noted in the comments). In short, the the front and back bands are constructed from two separate pieces that attach about 1" below the fold under the armpits. This seam is reinforced with a 1/4" elastic. Additionally, the front band is cut with more gathers for the outside layer that for the inside one. This allows for the inside layer to hold firm, while the outside layer drapes nicely.
I might insert breast pads as well, I am not sure (don't have any right now to try it).
The skirt is only basted to the bodice:
I am still not sure what I am going to do as far as color; however, after seeing the muslin on myself, I think I'll go with a solid.