True vintage plus size 60s mod dress

From the estate sale of a woman named Mary Stevens, who was a secretary at a furniture company in the 50s and 60s. With a classic 60s shape and bright color, she must’ve had fun in this dress. It is possibly handmade since it doesn’t have a tag. Has a subtle black check pattern. Waist: 46.5” Bust: 48” Shoulder to hem: 43” Model is 5’3” with a 42” bust and 34” waist, bra size 36D.