This is a 8502 Justin Alexander dress that has been altered for size and to add the sheer and jewel piece at the top.
It is a silk chiffon and silk duplon circular cut ball down with a sweetheart neckline that can be seen against the sheer addition. There is a loop to create a bustle on the back along with elastic button closures over a zipper. The chest/back piece at the top has buttons that continue from the dress line up the back. The dress has adaped waist and a gathered bodice with multiple layers of skirt. There are a few slight stains as shown in the photos. One under the left arm hole and one on the under side of the skirt.