I have two patterns in in my shops that are for ring collars, which are remarkably similar.
And this Ring Collar dress is of the two piece variety with a straight skirt and a pullover tunic. It is sized 10 to 16 and is vintage 1965 from McCalls.
Both are certainly attractive and an easy wear asset to our wardrobe. Personally, I'd go with the two piece dress and have the opportunity to pair up that great neckline with jeans as well.
These are listed in my shops, (see links under the pictures), along with lots of other knit dress patterns, should you be interested.
Thanks for dropping by.