Sycamore, as a pure guess depending on when initially AG plus wireless operator's sleeve badge or later S(ignaller) or perhaps whatever his previous entitlement had been. Flying Badges except for pilots seem to have been a complete dogs' breakfast in WW2. I refer you to Wg Cdr Jeff Jeffords' article THE LAW, AND LORE, OF RAF FLYING BADGES on pp103ff in the
Royal Air Force Historical Society Journal no 52.