Vintage 1980s Ruffle Lace Purple Blue Prom Dress

Could use a dry cleaning, has just been hanging in a closet. As you can see, there is quite a bit of discoloration under the armpits and a few other spots. This was my aunt’s prom dress in the 80s. Selling it for my grandma. Please note that vintage sizes run smaller than modern sizes. Measurements provided upon request.