Spitfire pilot – information sought

I am trying to find any information about a Spitfire pilot called Douglas Fletcher Clucas (rpt Clucas), who flew in the RAF. He hailed from the Isle of Man, born about 1921, and he served in the RAF from 1939 to 1946. We are uncertain as to whether he was commissioned, but we think not.

Any information on this man would be gratefully received. Any suggestions of where to look would also be appreciated. Thanks. John Shipman.