WWII vintage, khaki/tan US military officer or soldier's wool uniform shirt

Old World War Two vintage, US military uniform shirt. This uniform shirt is khaki tan and we believe it is wool. We're not sure what service branch (Army, Navy, Marines etc.) of the United States military it is from, but we've been told that it is an officer's shirt (or possibly a enlisted soldier's dress uniform). This vintage military uniform shirt measures about 19" long on the arm (from the armpit to the sleeve cuff), 42" around the chest (under the arms), 16 1/2" across the shoulders and 31 1/2" long from the base of the collar to the bottom in the back. This shirt is marked with "15 32" on the back of the neck. It is in very nice vintage condition.