Committed manual readers might enjoy a pass through the U2 Utility Flight Handbook from March, 1959, declassified two days ago. Pilots will see much that is familiar and plenty that is unique... surprisingly engaging technical writing for that era. (jalopnik.com) More...
They didn't release Appendix 1 - Operating Data...very interesting. Also, the Operating Limitations section leaves out Maximum MACH and Service Ceiling. Disappointed.