Oil Temperature Indicator, Dual Engine, Type A-24 US Army Air Corps WWII Czech we estimate that it is

we estimate that it is pre-WWII or early WWII era

This booklet contains fundamentals and tips for pilots of fighters and bombers on offensive and defensive tactics in preparation for or when encountering the enemy

The manual is hard-bound

The indicator marked for engines 3 & 4 has a 1944 manufacturing serial number prefix

which is available to download here

Oil Temperature Indicator, Dual Engine, Type A-24 US Army Air Corps WWII Czech we estimate that it isThe Army Type A 24 Dual Engine Oil Temperature Indicator was used across a number of US Army Air Corps and Air Force aircraft during WWII, including heavy bombers B 17, B 24, B 29, medium bombers B 25 and B 26, as well as light bomber A 20, according to the Accessories Interchangeability Chart dated Feb 1945. This A 24 was made by Sutton Horsley, part number 2213 7, and has a serial number prefix of AF42, indicative of a 1942 manufacturing date. This