Vintage Gunne Sax Gold Label Dress

Gunne Sax by Jessica McClintock button-down dark brown lace dress. Beautiful puffed sleeves and fitted waist. One pocket at the righthand waist. Excellent condition! Scarcely worn. There is some slight discoloration on the lace on the back of the collar (pictured). I have no size tag, but the measurements are approximately as follows: Length: 45 inches Waist: 13.5 inches Pit to pit: 16 inches I typically wear a US size 4 or S and can get this on, but cannot button between the collar and the waist. I would estimate this would fit a US size 0 or XS, perhaps a 2 with a small bust and waist. Please note that this is only an estimate. I cannot guarantee sizing.