Turn and Slip Indicator, Mk IA, 6A/675, RAF BOAC 25 inches diameter and ~5

25 inches diameter and ~5 inches deep

is a 38-page photocopy covering basic troubleshooting

true air speed

This example is definitely experienced by in good condition given its age

Turn and Slip Indicator, Mk IA, 6A/675, RAF BOAC 25 inches diameter and ~5Here is a Turn and Slip Indicator, Mark IA, Type 6A 675, invented by George Reid (according to the 'all knowing' Wikipedia) and made by Reid & Sigrist, as used on the blind flying panel of aircraft of the British Royal Air Force and the Royal Australian Air Force of WWII. It is an early version as evidenced by the all white markings; later versions had both white and green markings on the face. The Mark IA was used across numerous British aircraft