NWT Rare vintage dress by Expo size 8

Beautiful rare find new with tag vintage dress by Expo in size 8. It’s a form fitting dress and runs small! The front and back are reinforced. The dress is a mixture of rayon, acetate and nylon. The sleeves hang over the shoulder and have elastic. Is completely lined. Closes with zipper. To me it looks more like a size 6. Measured across from armpit to armpit is 14”.