I love this knitting pattern because it combines some great 1940's styling - boxy shoulders, deep waist ribbing, decorative stitches and a split neckline.
The neckline has two sets of buttons on either side of the neck, and was probably a nod to the Fashions for Victory requirement of 'functional' buttons only. It was a sneaky way for designers to use buttons for decoration but still have the function aspect covered.
If you'd like to read more - here's a link to an article from the The Mercury (27 July 1942) right here.
This jumper's finished size is 36 inches, and is knitted using fingering weight yarn on 3.75mm and 3mm needles.