Vintage Blue TWO Piece Dress and Coat

This is a unique one. True vintage. Union made ILGWU. TWO pieces. High neck blue sleeveless dress with a zipper and two original clasps. Sequins/thick embroidering throughout. A heavy substantial piece. Slit in back of dress. The coat is floor length also has embroidery/sequins. None of them appear to be missing. Clasp closure on coat. No size tag, I would say it's a small because it's a vintage piece. Smoke free home. Small flaws in the material I want to say it's polyester but I'm not sure.