Seems like some here don't know the difference between a leather jacket and a sheepskin jacket.
As far as wearing an RAF pattern cold weather jacket goes......Having been obliged to wear one for almost twenty years, because it was uniform, imho it's not a very good jacket, especially by today's standards (possibly so called because it makes cool weather feel like cold weather and they are not waterproof).
Whatever you choose, just don't buy a cheap nylon jacket. In any sort of fire they melt into your skin, making the injury far more severe.