This feature ("cut on gusset") is better known as a "pivot sleeve" and can be designed in any number of ways. I have a scan of a draft (circa 1952) on my site that shows a peaked rather than rounded gusset. I'd leave a link but don't know if this will post. Google pivot sleeve and you'll find it on Fashion-Incubator.

The pivot sleeve is not intrinsic to Norfolk style jackets, they can be put into any garment with a suit sleeve (I've put these in blouses). George Mallory wore a jacket with pivot sleeves made by Burberry on his Mount Everest summit that became very popular at the time. I doubt Mallory's jacket was a Norfolk being unsuitable for climbing; those jackets are rather like sport coats with box pleats at the center back or two box pleats off to either side of the back. Originally, the Norfolk was a gentleman's shooting jacket.