Vintage Lilli Ann long women's dress size medium ( see measurements)

Gorgeous! Gives off vibes of some top designers from modern times except that this is super vintage! Lilli Ann was a high end brand from the 40s, 50s and 60s. I can not confirm material, size or age of this dress as I can't find one like it anywhere. Missing bottom button as pictured. Has shoulder pads. Buttons and spans on the inside.