Vintage Nordstrom brown trench coat

This is a VERY vintage Nordstrom coat, the tag is dated early 1970’s per the Vintage Fashion Guild. I am the second owner of this coat and I’ve only worn it once. I love it, but it has just been sitting in my closet as it doesn’t fit me anymore. The tag does say size 10, but I am a size 8 and I can barely close it. I would say it is more a size 6, at largest.