These two clips found on You Tube are wonderful. The description says both were filmed at the police training college in Cwmbran (now closed) in 1984.
The trainees singing the Beach Boys’ ‘Sloop John B’ is very entertaining. The second one shows the passing out parade with the officers marching into the large yard to be met by the chief constable.
The quality of both clips is pretty impressive considering this is 27 years ago. I’ve emailed the person who posted them to try and find out more about the people in the films. I hope you enjoy them as much as I did.