Vintage San Francisco Shirt Works flycollar S/XS

Vintage San Francisco Shirt Works summer green flycollar top decorated with belts aligned in block patterns. Please check measurements. Will fit like a small, XS. Measures about 18 across from pit to pit. There is no stretch/ give. Darting to abdomen for waist cinching. In good condition, no rips or tears. Has slight pink coloration to wrist- see pics.