About 2,500 union workers at Boeing [BA] manufacturing facilities in the St. Louis area could strike Aug. 1, the St. Louis Post-Dispatch and other news outlets reported Sunday after members of the International Association of Machinists and Aerospace Workers District 837 voted to reject a contract offer. The St. Louis area plants specialize in national defense work including aircraft such as the F-15, F/A-18, T-7A trainer and MQ-25 unmanned aerial refueling drone. “These highly skilled members fabricate, assemble and build…