70’s does 40’s vintage polka dot dress

Found this gem thrifting. I ran it by my Grandma, she agrees with me it’s around a 1940’s homemade dress. Her exact words were “looks like something my mother would have worn” Though the fabric feels more like it’s from the 60’s or 70’s. It’s a little too big for me, though I am thinking some curvy pin up would look darling in this number paired with a fluffy petticoat. Would fit a size medium to large best in my opinion.