I recently obtained two 1943 issue Flyers armored vests which appear to be scarce.
From the history of WWII personal armor - - - "Due to the effectiveness of German defensive fire, crews of the USAAF bombers sustained high casualty rates. 75% of those killed or wounded were as a result of being hit by low velocity fragments; therefore the ability to provide protection as encouraged by 8th AF Surgeon. Col. Malcolm Grow developed alongside the British Wilkinson Sword Co. a solution in the form of an armored vest. Made of two pieces the vest comprised a front and back and featured several 2" square manganese steel plates encased in pockets and covered in heavy duck material. After a 1942 trial the first sets were delivered for operational use in March 1943. The first 600 sets were produced in England and samples were sent to the USA so that production could begin there with a priority. The US manufactured vests were covered with dark green material. The vests were issued to gunners, navigators, bombardiers and radio operators. The flyer's vest M-1 was undeniably heavy and cumbersome, however it successfully saved lives. The casualty rates of men not wearing flak protection were 36% killed and 69% wounded. With use of the armored vest protection casualties were dramatically reduced with only 18% killed and 13% wounded. An impressive 69% of the vests that were struck resulted in their wearers being unscathed. Flyers soon overcame their reluctance to wear the heavy vests and quickly learned to don them only when under fire to avoid unnecessary exhaustion knowing they could jettison the entire system by a quick release action in case of an emergency (red pull tab as seen on the vest).
The first photo is most likely on the 600 or trial vests that were made by the British for the U.S. Flyers. It is unmarked and has the heavy duck material and manganese steel plates in the front section. The 2nd vest is marked as an M1 with an M2 back and is covered with the dark green material as identified as the first U.S. Manufactured vests.
Pilots and Co-pilots normally wore these type of vests that only had the armor on the front. Interesting pieces for research and addition to any early WWII flyer equipment.