1960s Vintage Brown Sleeveless Midi Dress with Embroidery

Gorgeous 1960s fit and flare sleeveless dress. Brown fabric (nylon?) with embroidery detail. Bow detail at waist. Fully lined with an acetate fabric. Metal zipper at back. I see a few very faint stains on the embroidery on the overlay fabric, but other than that in great condition. No fabric content tag or designer label. Marked size 13. Dimensions laying flat: pit to pit 17". bust 16". Waist 13.5". Hip 23"+. Length 37".