Sophisticated vintage dressy black dress

As a child, my Mom regaled me with stories of my beautiful Grandma getting dressed to the nines and stepping out with Grandpa who was very dapper himself. This was one of her favorites, circa late 1950s. Sleeveless with a lovely lacey shawl like collar and long back zipper. All labels are missing but I’ll try my best. Definitely dry clean. Fabric is almost like a shantung, wearable every season. Laying flat, I measured 18”across the front, armhole to armhole. Take into consideration that Grandma was very bosomy, maybe a C cup. Around the pleated waist area, I measured about 16” across the front. From shoulder to hem, measures 39”. Please contact me if you need more specifics. My best guess is a size 12. Great condition except needs to be re-hemmed. Refer to photos. So, step out in style with this beauty! Oops, forgot to mention, Grandma pinned a large pink rose to front of dress. Looked super! 🌸