Beautiful Vintage Sequin Dress.
Marked British Colony of Hong Kong.

My guess is Size 2 is the best. (Marked Sz 8)
shown on Size 4 model & Mannequin….a little tight in hips and torso for her.

38.5" long
25" waist 
16.5" pit to pit
17 3/4" hips flat

Great condition.
There are a few sequins missing on the top of the sleeves but
not very noticeable since they are on top of the color, so just the color is showing.