TTN,
Ward Thomas, Gwyn Edward "Ward" Thomas, was certainly on the Bowen-Bravery crew of 550 Sqn. and is definitely shown as the Nav. 550 Sqn. was formed out of 100 Sqn. at Waltham in November 1943 so it is most likely that he was part of the same crew on 100 and thus probably a Nav as well. On the formation of 550 the crew photograph shows him as a Flt Sgt which would fit after a year or so on 100. 100 Sqn was re-formed at Waltham in December 1942 out of the same Sqn that was in Singapore and then Australia becoming 100 Sqn RAAF. After the war he became a pilot with Swissair which leads to the puzzle did he first qualify as a pilot. I certainly know of a gentleman near here who qualified as a pilot about that time but when he arrived back in the UK was told that they had enough pilots and he became a Rear Gunner on IX Sqn. so the same may have happened to your man.
ACW