Southern Aircraft Gatwick Engaged On National Service war workers badge

A very scarce original Second World War period 'Southern Aircraft Gatwick Engaged On National Service war workers identification badge', brass example depicting a blue enamel title surround and central red enamel inscribed 'Engaged On National Service', the reverse impressed with maker's details 'Thomas Fattorini Ltd Regent St. Birmingham' and impressed with low issue number '81'. Good condition, no enamel loss but with dark marks to centre and minor service wear.Diameter approx 23mm.Southern Aircraft (Gatwick) Ltd. was a company working under contract to the CRO at Gatwick Airport Sussex.