I'm struggling to work out what the NEF bit stands for, but when he signed for receipt of his war medal he just gave his unit as Royal Engineers (https://www.ancestry.co.uk/sharing/7797393?mark=7b22746f6b656e223a224537705a6d65512b5a74786b66477879476f34474455355055386b4b73326845475a786e705267743051673d222c22746f6b656e5f76657273696f6e223a225632227d)