The CFS badge was applied to the first six jets to arrive at Valley IIRC and were just 'in the pool' not specifically allocated to CFS Pilots. CFS used to fly almost exclusively of Sparrow hawk line and I definitely recall CFS marked jets operating from Goshawk and eventually Seahawk lines on solo student sorties.
The other big changes I saw from when I arrived in '79, were the nose numbers going from black to white to make it easier for the line walkers to spot; and the pyramid and palm tree growing in size and gaining a ring around it.