BOAC
The units in which the rotation of the ADD (Airstream Direction Dectector) probe was measured were as near as dammit degrees. Hence 8 ADD was (allegedly) pretty close to 8 AOA at the wing. As Bill said it mattered not to us whether they were actually degrees of (wing) AOA. What mattered (as I know you realised) was that you flew the right number in order to give a sensible margin from the ADD value at which the wing stalled. For flight test analysis purposes there were charts that corrected ADD readings to AOA values where the aircraft did not have a typical flight test vane on the end of a boom sticking out in front of all the local effects caused by intake flows and so on.
John