Vintage vest. Men's or unisex, s\m

This true vintage vest is from the '70s and belonged to my father. It is in very good vintage condition. Has two front pockets, and buttons up the front. The back of the vest is knit and the front of the vest is like a wool. Not sure if it is real wool or not. It is labeled a medium but this is a vintage size. Today it would fit a men's small or a women's medium