From the McCall’s description:
Mesh fly-away sleeves, a filet crochet “bib” framed with spider web patterns that continue across the shoulders and encircle the waist--these lacy elements combine in a unique summer fashion. Butterfly Top, the same front and back, has little ties at the side for snugging the waistline to fit.
Note that exact size is not critical, although the length is. There are no sides to this other than the waist band. The “sleeves” are actually semi-circles picked up from the vertical side bands of the “bib.”
The original thread called for came in 350 yard balls, so the yardage given here is probably generous.
Actual publication date: 1976