Artillery Firing Calculator, USSR, 1944
True, this is not aviation in nature, but it is an exceptional artifact from WWII.
This is an original Soviet Army Artillery Firing Calculator, used in determining proper elevation and deflection (direction) when operating field artillery weapons. It was carried in the map/document case worn by a Soviet artillery officer. The calculator contains diagrams and a graph, with rotating wheels and tabs, and made of material which permits writing-in pertinent data to calculate a firing solution and erasing thereafter.
When folded, the calculator measures ~8 inches by 6 inches by 1/2 inch thick, and ~16 inches by 8 inches x 1/4 inch thick when opened. It is constructed of a stiff, faux-leather over cardboard, with contents stitched and riveted to the interior. The cover is printed in gold Cyrillic letters: DEVICE FOR CORRECTION OF FIRE, MODEL OF THE YEAR 1944, along with the symbols of the Soviet army and the manufacturer. It is in exceptional condition given its age.
Imagine you are a 22 yr old Soviet artillery officer under pressure from your Soviet General (with the political officer looking over your shoulder) while trying to use this device to determine critical mathematical calculations and avoid the consequences of friendly fire on your front-line comrades (not that the political officer cared about that). Not for the feint of heart!