View of workers assembling and machining trunnion shafts and brackets in Engine Assembly Area at Plant 1, GMC Truck & Coach plant. Printed on front: "GMC Truck & Coach Division." Handwritten on back: "Plant 1. 1st floor Engine Assembly Area, Bldg. 5. Assembling trunnion shaft & bracket assemblies on line operations, Dept. 9. Factories--GMC, ca. 1943."