Vintage Tom Bowker for Coterie Floor Length Beaded Gown, sz 12

Purchased in late 80's from a boutique and worn once. Full length black satin gown, wrap skirt with tulip hem that gathers in front with a flounce. Spaghetti straps with iridescent beads. Zipper up back. Made in England. This gown is labeled a size 12, but may be a small 12, so please see measurements. No label regarding material. Dress length including straps: front- 54", back- 57" Arm pit to arm pit: 17" Waist: 14.5" Hips: 19.5"