Dark blue worn 1940s/early 1950s chore jacket in an XS size (18.5" pit to pit), made by For with a nice inner label. Exceptional piece.
Classic cut with 3 patch pockets with double stitching (shows item's quality), 5 black front buttons, one inner pocket, small collar. Great character. 
There are two labels, 'For' the manufacturer and 'Boussac' the fabric brand, Boussac was at one point the kind of fabrics in France with factories throughout the country. It was a mark of quality.