Vintage Sequin Dress(Unknown Size)

I didn’t see a name, or a size! But, using measuring tape, from shoulder to shoulder, it was “21; across the waist was about 19”; from a shoulder down to the end of the sleeve, it was around 27” long. I don’t know what size that constitutes as, but I’d guesstimate a bit on the medium/large-on-the-cusp-of-XL side. Uncovered from a cluttered and dirty closet that hadn’t been used in at least a decade, then washed twice. It’s got some weight to it. Also has a small slit on one side, open back area, with a back zipper. Being sold as is! Some sequins might be loose, or missing. Please take good care of this dress!