Absolutely  stunning and probably custom made, no labels. Worn in the 1940s.
Please note this is a lovely  dark solid black, some of the photos are lightened to show the detail only. 
Flange on the shoulders.
Shirring yoke,
Lined with  charmeuse.
Discoloration at the top back neck on the lining. Otherwise all perfect.
Two velvet fasteners at the front neck.
Very  cool piece. 

Probably  best on a small to medium frame, the mannequin is about a modern size 6, and it fits her very well.
The chest area circumference is 62"   and at the hem the circumference is 68".