If my memory is correct (and it might not be, it's forty years since I will have seen him) the chap on the left is Matt Miller, a Canadian who was later at Shawbury working at RAF CFSH.
He told me a tale of test flying the then brand new Gazelle over Salisbury Plain one night, hovering and shining the landing light on a courting couple's car and causing a "UFO" scare in the local rag, probably because of the Gazelle's unique sound.