The rank badges Old duffer described in his post on the post-war aircrew rank structure are amazingly scarce. In thirty years of dealing in militaria I was always on the lookout for these but I dont think I ever managed to get hold of one. I did see a full set being offered at a militaria fair once for an astonishing price. I did however once have a GSM named to an "S 2 Bloggs, R.A.F." (Flight Sergeant Signaller).
When I was a rockape we had a squadron leader with pilot's wings - I think he was WW2 vintage, had gone out and come back in later but wasn't accepted as aircrew second time around, but of course was still entitled to wear his wings.