Deadstock salt & pepper coveralls made by Dutch workwear company KLM, 'Kan Langer Mee' (It lasts Longer), circa 1950's. KLM is a shared name with the Royal Dutch Airlines, for which the workwear brand used to make clothing. Single back pocket.
 
Rare and highly sought after piece of workwear. 
Tagged a size 52 (Men's medium/large)
 
Measurements in inches
Shoulders 18"
Pit to pit 24"