Vintage Designers Choice men's blue short sleeved dress shirt, neck size 16

This is a vintage men's Designers Choice permanent press short sleeved dress shirt in blue, size large. It has a single pocket and buttons down. Neck size is 16-16 1/2. It's in nice condition but has a light stain on back at waist (see pic). Measurements: 19 1/2" across shoulders, 24" armpit to armpit, 29" base of back collar to hem.