Vintage 1930s French HBT cotton chore jacket/work shirt with awesome "ghost pocket", character mends. Concealed button fastening (mismatched) , buttoned cuffs, patch pockets. Light weight and unlined so could be worn as a shirt or jacket- nice for layering.
Herringbone twill (HBT) has a very specific surface, which looks like a fish skeleton. This is the reason why this twill binding was twill or Herringbone twill. Throughout the centuries in men's clothing, twill with its continuing diagonal weave in one direction was very commonly used.