1930's vintage chore jacket with locomotive change buttons

RARE 1930's depression era, chore/railroad denim jacket with locomotive train change ring buttons. The jacket has a very early design with one chest pocket with the side slash; the denim has a great patina for his age. All the three buttons are present with the original rings, single button cuff with hash marking - there is a period repair at the lower back at the back of the jacket (email me for additional photos).
The jacket measure chest 20" shoulders 16.5" sleeves 22.5" length (from collar) 28".