Vintage USMC Marine Uniform Shirt Size 15 - 15 1/2

Vintage Short Sleeve Marine Uniform Shirt Not sure of the age of this, based on the label I think its 60s or 70s I am not sure of the rank - but a kind fellow ebayer advises me that its Gunny Sargent and the crossed rifles is the symbol used for all ranks of USMC; I'm not an expert though Size 15 - 15 1/2; length from center back to bottom 31.5 inches; 23.5 inches from armpit to armpit I don't see any imperfections on the shirt - but it is vintage