Vintage 1960s Mod Dress Round Neck Zip Short Sleeve Floral Yellow Size Medium??

Brand: Unknown ( Possibly customed tailored) Type of Clothing: Women's Dress Condition: Good condition. Some yellowing front neckline. (It may or may not come off) Details: A line dress, above knee, Short sleeve, back zip closure ,small flowers print, tuck pleats and lace design/adornment in front of dress.Please check all photos. Materials: Feels like similar to canvas but lighter (no fabric label found) Color: Yellow Size: Size Medium?? (No size tag found).Please refer to actual measurements listed below Actual Measurements (Approximately laid flat) Shoulder to Bottom Hem- 38" Underarm to Bottom Hem -28" Underarm to Underarm- 19"