Most likely vintage 2 piece Due Per Due 2 piece long sleeve low mandarin collar heathered plum button jacket, and coordinated scoop neck mauve sleeveless top, both size 16W.

The jacket is a two tone dark plum and medium mauvey plum color made of 55% linen/45% silk, it has snap in our out shoulder pads.
The popover cami top is mauvey plum with a semi satin sheen made of 77% silk/23% linen, both pieces pop and blend with black pants or skirt, both in excellent condition.

Following are the flat, relaxed external, closed measurements, some of which are doubled:

 Top-Bust-pit to pit-48"    Waist Area-47 1/4"     Bottom Circumference-50"       Length-24"-has 3" side slits

Jacket-Bust-pit to pit-49"     Waist Area-49"     Bottom Circumference-51 1/2"     Length-28"-has 2.5" side slits
Shoulder to shoulder-18"/Sleeve length-23 1/2"