WW2 Air Transport Auxiliary ATA officially numbered pilots badge

A rare original Second World War period 'Air Transport Auxiliary civilian pilot's unmarked silver ATA pin badge bearing the motto 'Aetheris Avidi' (Eager for the Air), the reverse impressed with official issue number 'D 1243'. Very good condition, retaining the original pin fittings, safety roller catch now absent, but not affecting the functioning of the hook. Height approx 29mm. Air Transport Auxiliary formed in 1939 and based in White Waltham, Maidenhead, Berkshire. It was disbanded in 1945.