As I said, Sopley was originally a fighter control unit from the early/mid 50s rather than ATC, the radar being unsuited for airfield work but suitable for area work. I'm not sure when the civil element started there but obviously it was not 1958!
There was a 'joint' area radar training school (ie training both civil and military controllers)at Sopley until the late '60s.
Going back to the College of ATC at Hurn, the Doves were controlled by students and instructors using consols in Bournemouth Tower alongside the 'regular' controllers, the college never had its own radar..