Vintage full length gown

Take your breath away pretty. This gem has no tag. I’m guessing 70’s from the style. Pretty enough to wear in public as a statement. Sheer royal blue color. Capped flutter sleeves with plunging neckline. Gather pleats on front attached to ribbons to tie in back for cinched waist. High slit on each side. Scallop stitch hem details. No flaws. Looks to be a small. Also arm opening is small. Laying flat Waist 18” at largest Pit to pit 16.5” Arm opening 7” Length 55” Slit up from hem 25”