For all 4 seasons (5 coming soon) Thomas Shelby has worn the same suit with only some moderate changes in the last two seasons. Set in 1919 which was somewhere in between Edwardian fashion and roaring 20s style there was the look of the Jazz Age. Men’s Jazz suits that had slim fitting high waisted pants with a tapered cuff hitting slightly above the ankle, a narrow shoulder sack suit coat (loose and straight) with peak or notch lapels, and matching 5 or 6 button vest. Only the upper and middle classes could afford a new suit, most people living in Birmingham would have worn older, second-hand clothes that may not have matched or fit well. Wearing a suit without a vest was a common sign a man was working poor. Shelby being a man of the lower class but having some wealth dressed a little better than the neighborhood gang but was also careless in his choice of clothing.