Very interesting technical photos and info on a vintage aircraft! I asked around and it may show a Convair and a commercial airliner. If you know better, please send a note. There is a 3-ring binder containing over 40 photo images and 10 blueprints, all about 8×10 inches. They date around 1946 (WW2 era). There are numerous handwritten notes on many of the photos and it is surely some type of quality control inspection. Minor general wear as expected. Along the binding the 3-hole punches have lightly creased and curled the photos. Vintage original binder shows extra wear.