Based on silhouette, metal talon zipper and placement of bust darts, I believe the dress to be 1960's.

Yellow floral lace outer with lining. Center back zipper. Front boat neckline with v-back and back vent.

No size or fabric content on tag, measures like a modern XS. One tear to the lace on back left shoulder. Lining feels like acetate and/or nylon. Unsure of lace fabric composition. There are stains on the inside of the lining, mainly on the bodice and underarms. Stains have been gently treated with vinegar. They do not show through to the front.

Actual measurements:

bust: 32"

waist: 24"

hip: 36"

length: 42"

This item is sold from an excellent, highly rated vintage boutique in El Cajon, CA.