ponents and air-conditioning ducting, precision-machined metal products for missile guidance systems, computer memory drum components and eleetro-meehancial assemblies.A CONTRACT FOR WORK valued at more than $1million has been awarded on the McDonnell Douglas F4 toAeronca Inc. . , ^'The work involves production of aluminum aircratt substructures which' utilize Acronca’s extensive .stretch-forming capabilities. Acronca’s Torrance division of its Aerospace Group will manufacture the F4 structures.