Vintage late 80s Victor Costa stunning Purple ruched gown bow back

Vtg late 80s Victor Costa stunning Purple ruched throughout large bow in back the tagged size is a size 8 but this is vintage sizing and the mannequin is a size 6 and it is a good fit therefore I am listing this as a size S. This dress has been altered in length so please see measurement photos. Large back bow. Petticoat underskirt in the back on bottom There is a hook closure at the top of the zipper and the loop is missing There are some marks on the underside hem of the skirt