srm is spot on for how we used to measure. 12' up for light wind, 24' up for medium, and 36" up for high wind. In the US we got away from this technique with the introduction of the comptip. Now in the US most sail with snug diamonds. Rake was measured by placing mark on mast 4 feet up (I think that was right). Measure from for stay anchor to mark. Range was between 105.?? and 107.??". If they are heavy put them at 105 for power, if light put at 107. Side stays were loose enough to allow mast to rotate 90 for downwind. (pretty loose compared to todays F18).