This is the early Suits, Aircrew pattern, not the later War Service Dress, the main difference being the internal field dressing pocket on the trousers.

I managed to find some of these unissued mittens in the same WWII shade of khaki as the gloves.

Reproduction. This is the British knit cap commonly associated with Commandos, but actually issued to all British soldiers. To operate, you put your fist in one end, make a sock puppet, and roll it up (yes, many people ask). My repros are an exact copy of the WWII version in light khaki color. A limited supply has just arrived.