Who is the other fellow?

I think he is a Staff Sergeant of the Royal Engineers who was creating the new playing fields. See 1966 Magazine -"Another important new facility which we hope to get are some playing fields of our own, near the school, and we are grateful to the Army for having undertaken to do the initial levelling of the ground, as a training exercise. When the grounds are ready they will be most welcome: we have found it increasingly difficult to get enough service pitches since a number of service establishments have closed down, and it is a great waste of the time allocated for games if the children have to spend 30 minutes or more of it travelling in buses."

Thanks for the clarification Dave