two-tone dress

This little dress has never been worn! It looks like 60's or early 70's. Pale purply (mauve) color on top, off white bottom and blue with cream flower applique. There are little spots which look like mold. Wondering if dry cleaning would take care of this. One dark spot on the back (about 1/4"). Nylon zipper on back. Fully lined. The label lists the size as 12, but this is the old sizing. Bodice is 100% acetate, as is it's lining. Skirt is 65% supra rayon and 35% silk. Skirt lining is listed as 100% cotton, but I question that.