In 1947, Christian Dior launched what came to be called the New Look with long, wide skirts, soft shoulders and small waists. The style survived into the 1950s and gives us this 1956 coat which has just been re-issued by McCalls in modern sizes.
The princess seams and darts shape the coat to the body through the bust and waist, and then gives us flares at the hips where the pockets are also placed. As a result, it takes around 5 yards of fabric at 60″ wide depending on your size. It offers either a large or small shawl collar. The pattern suggests lightweight woolens like gabardine, as well as tweed and boiled wool, and wants us to underline all the pieces. But why not skip the underlining and make sure your fabric has a bit of body to it to begin with? I am thinking something a bit lofty like a wool/mohair blend, or a tweed with some weight to it. Gabardine, by the way, with its hard surface and tight weave. is hard to tailor and shows every mark; better to go with something that has softer face like the nubby black and red coating that you see in the photo.