As others have said. This was the 1946 Aircrew Scheme. Details on the rank badges here:
https://www.rafweb.org/Ranks-Uniform/Ranks6C.htm
As for the Pilot Flying Badge (never, ever, a brevet as that is French for a certificate or diploma). In the 1950s a full size bullion flying badge replaced the white/ecru silk ones and also the lower pockets were removed from the No 1 Dress jacket. It looked awful.
It was known as 1947 pattern and there is more detail here:
http://www.britairforce.com/imagepag...iform_1947.htm
You can see Sir Frank Whittle wearing one here in this painting along with the gold flying badge:
So I reckon you could date your photo to between 1947 to 1950 (ish).