Vintage Floral Dress with Belt

“Tabby of California” purple floral dress comes with belt sz 6? (Number stabbed on inside of belt Shoulder pads Button closure on one shoulder, other shoulder with matching buttons Measurements taken flat: Armpit to Armpit: 18-19.5” Waist: 15-19” Length front: 38” (from neckline) Length in back: 40” Might be size 6. Should fit like small or medium.