There are plenty of the other Brevets on ties but, seemingly, no AE Brevet
At the risk of breaking PPRuNe rules on advertising I can say that I sell regimental ties, including RAF. A while back I had an enquiry for an AEO tie, and the manufacturer I deal with told me they no longer make them, so I'd advise anyone looking for one to take advantage of the OP's offer. By the way £20 for a silk tie, particularly one with a brevet (or whatever you want to call it) is very good value. Funnily enough "my" manufacturers still supply air gunners' ties - must be old stock I should think!