PS. I recommend Jeff Jefford’s excellent book on “non-Pilot” Aircrew that reveals the full story on Air Gunners prior to World War 2. There is a great story in there about the Air Gunner’s Flying Badge, where the original remains in the National Archives as pictures below:
This badge was presented to CAS prior to going to the Palace for His Majesty’s authorisation. However, the sharp eyed CAS noted that there were 13 trailing feathers on the wing and deemed it ‘unlucky’. So a PSO or SASO was tasked to find a pair of nail scissors to trim the 13th feather off, which if you look above can be seen by the gap by the khaki wreath. All RAF single-winged flying badges have had 12 feathers ever since (apart from the odd erroneous one in stores). This was again corrected in 2019 with a batch of WSO/WSOp Flying Badges in stock.