I did a bit of research and the T/W logo is T. Williams and the A/F is "across the flats"
All of the sizes are marked "A/F," which stands for "across the flats," a distinction made from the previously more common British Standard Whitworth, a standardization for threads that considered the diameter of the threaded shaft as the measurement, not the size of the nut or bolt head. As Whitworth was being phased out at the time, the included wrenches were marked as what we would now consider SAE or standard sizes and distinguished with the "A/F" marking.