Official Caption: “Dec. 1942: Production. B-17 heavy bomber. An Army sentry guards new B-17F (Flying Fortress) bombers at the airfield of Boeing’s Seattle plant. The ship will be delivered to the Army and the Navy after they have successfully undergone flight tests. The Flying Fortress has performed with great credit in the South Pacific, over Germany and elsewhere. It is a four-engine heavy bomber capable of flying at high altitudes.”

Photo by Andreas Feininger, Farm Security Administration – Office of War Information Photograph Collection (Library of Congress) LC-USE6- D-008483
The MP is attired in a mix of Doughboy and 1930’s gear with a 10-pouch belt, M1917 Brodie helmet, wool gloves, pre-1938 single-breasted overcoat, class B uniform complete with tie and khaki canvas leggings. His primary arm is a Winchester Model 12 riot gun.
As noted by Bruce Canfield (Complete Guide to U.S. Military Combat Shotguns), factory records indicated that Winchester delivered 61,014 Model 12s to the government between April 1942 and March 1944 in a mix of riot, training (field) and trench variants. These remained in use through Vietnam.
As for the B-17, Boeing would produce 6,981 of the iconic four-engined bombers, slightly over half of the aircraft’s 12,731-frame run. While the Seattle plant would crank out 2,300 early B-17Fs as in the photo above (note the two-piece bombardier’s nose glazing and lack of a chin turret), the majority– 4,035 bombers– would be the legendary B-17G, which bristled with 13 machine guns.