Please can anyone help with the identification of this man's uniform. So far, I think he may be a Special Constable wearing an 'on duty' brassard. However, if he is a Special, I am struggling with the cap badge - having looked at the examples on this topic (of which there are many!) the nearest I can get is Guernsey (or Salvation Army!!). Unfortunately, although I have tried to enhance the picture, I can get no further detail.
Does anyone have any thoughts/ideas about date, etc?