The rubber coats were mainly made by Pytchley. Yes, I've worn them! Ever tried running in one across short heather after a bolting race horse with several pounds of lead in the pockets? What isn't obvious from the picture is the rear vent is very wide and long, but has buttons down it so that it can be closed up when walking. This allows it to spread back over the saddle, so the rain dosen't blow in up your a**. The long ones also have inside straps to hold the coat closed against the legs. The pockets are also cut much higher than a standard coat, above the waist. Because if you sitting on a horse, the coat will splay out from the hips down the horse. a lot of Brtitsh army uniform at that time was modeled on 'sporting', ie 'Unting , shooting, fishing and Golf, clothing fashionable at the time.