Vintage Military Men's Green Wool Jacket Size 38 R (Medium) Field Jacket Heavy

This is a vintage men's military jacket. Unfortunately, I don't know much about it and it doesn't have much to identify it other than the size tag (38 R). It is quite heavy - over two pounds. It feels like wool and looks to have a cotton lining. There are a couple flaws, most noticeably a small hole under one pocket flap. Not sure if there was a snap or something here or if this is a moth hole. There is also an area of discoloration on the back. It's faint, but you can see it in the right light (this is shown in the last pic). I did not try to remove it and it may be removable. I measure the chest as just over 38 , shoulder to shoulder is 18-3/4 , shoulder to wrist 24-1/2 , and length from back of neck to bottom 23-1/2 . Thanks for looking!