Not vintage, these 1960s-style shift dresses are available on the high street (and online) at Oasis.
Two very 1960s designs there right now, both quite simple and all the better for it. The yellow dress above has short sleeves and some button detail tabs around the waist, while the A line red dress below has buttoning all the way up the bodice, creating something a little more unique. That one is also available in black if you don’t want to wear something bold.
As we said, both are available online right now, selling for £50 and £55 respectively and in sizes 8 through to 16.