Confirmation - brevet ID and period

[david1812]

THIS Half-brevet came to me with the medals of a South African WWII artilleryman - which means nothing as in my experience as a very long time medal collector, it was quite common for men to exchange/collect insignia, etc at the time - most of which ended up with other badges, buttons and sundries in an old cigar or chocolate box. Anyway, from what I know, this appears to be R.A.F. and obviously an air gunner. BUT whereas most such brevets are embroidered silk or cotton, this badge is bullion wire - as can be seen. It is in excellent condition - virtually pristine. Here is both the Obverse and Reverse in the illustrations. So what I would like to know from an EXPERT is the exact details of the brevet, please - including when, where and how it was used. Thank you.