I just found an odd hunting jacket. My gut is sending me into the late 1930s or early 1940s, because of the pointed collar, the cut on the pockets and the amount of material used.
It's in a buffalo plaid pattern but multi-coloured, which I've never seen before. There appears to be venting on the sleeves, the front and the back but when I snake my hand up into it it's sealed at the top so it's simply another layer of fabric. Maybe for warmth; maybe for protection.