If this is our man then the London Gazette gives:
wef 25 Sep 42 FSgt Samuel Da Costa 932716 -> 136049 RAFVR A Plt Off
wef 25 Mar 43 A Plt off to Plt Off (prob)
wef 13 Oct 44 Fg Off to Flt Lt War Substantive S Da Costa 136049 which justifies the shoulder bars.