Vintage 70’s Navy Polka Dot Secretary’s Midi Dress

Great vintage 1970’s 3/4 sleeve navy blue polka dot with white trim and buttons on the chest. Very secretary style, side slits, elastic waist and midi length. There is no fabric tag but feels like a polyester. Vintage size 18 more of a current M or L, please check measurements in photo! Missing the belt but otherwise in good used condition!