Rare & Unique WWII AAF Restricted Tech and 11 similar items

Looking at the last page of the sheet metal manual it is easy to see why these were so restricted, you could use the tables there to figure out what you have to do to shoot through some. I can't get a good shot of the security warnings in the two 1939 books without folding the front covers back too far but they are very bold and straightforward. Not counting covers the starter motors manual is 64 pages, the ignition system manual 24 pages counting blank sides, and the sheet metal book has 70 pages which I believe is complete, the last citation in table of contents is page 67. All three have light staple rust but otherwise not looking too aged and not having much wear at all. It is possible, perhaps probable but not certain that one or more of these belonged to the individual named in the rating certification and who saved that along with what may well be the only surviving copy of the program for his graduation at that school. If I had the omniscience to know I might bet in advance that somewhere in this world there might be another in a forgotten scrapbook in someone's attic, but basically you or I will never see another. Both are a bit wrinkled. The program could be easily restored to crisp and flat merely by soaking then pressing just like you would do to take a stamp from an envelope; the certification slip has a water based ink signature so don't try it with that.