Seaking,
The PP is included as it is an authorised training aircraft for the Historic Flight, but no matter.
Beagle, I am not too sure whether much else was 'expanded' in the 50's. what was more significant was the development of the 2 very large hangars, offices and hard standing on the South side, together with the redevelopment of the western dispersals and hangars for the Lynx and Seakings in the 90s.
However, to see £100M invested is fairly major in today's constrained times.