70s Vintage Joseph Magnin Mixed Print Floral Prairie Dress Long A Line

Excellent used condition, the split neck extends further than the buttons and there is the same split in the lining underneath. My first thought was maternity? But either way it could be left as is or sewn up. Acetate material, most likely - Woven Button neckline Ruffled Collar Short puff sleeves Lovely fit and flare a line shape Midi length or longer skirt, pleated Swiss dots, plaid, and florals - Gunne Sax style Lined I believe this is 1970s No size listed. Measurements are 38” bust, 47” long.