The Surveying Tables manual has no back cover and frankly is completely boring but it is basically a throw-in with something else somewhat mathematically oriented, one of you may as well have it as leave it sitting here. Army Air Force manuals are not so common as the broader service ones and the Celestial Air Navigation revised 1942 edition is kind of cool and of importance to you might be that there are some number of photos of field gear and equipment that you might encounter today. So off into the blue yonder and please bid promptly. AAF manual is G/VG but not brittle, pages tight, has markings on front but they add historical value as it belonged to a group instructor although not named.