They weren´t civilians. The parachute packers were WAAFs. One of them was a corporal. (And I do know that there are people on this site who don´t believe that the RAF is a military organisation). This was back in the days when parachute packer was an RAF trade for women only. From what I´ve read on here parachutes are packed by contract civvies nowadays.
Did anyone else notice the class of black students standing in the lower foreground during the exit training scene in the hangar? I guess these were Commonwealth personnel that were being trained up.
Anyone spot the lass with her PJI helmet worn back to front prior to entering the ballon cage?
As for the Commonwealth student group - they were most likely potential instructors for their own para school in Kenya, Nigeria or Ghana. We had a team of instructors based in Gil-Gil ( Kenya) before it was closed down in the early '70's.