The source is me, my dad worked for a GMC dealer and we had new trucks around most of the time during those years. Dad owned a 1949 model that we used on the farm when the 1950 models were introduced the new demo had the tailgate letters painted so he painted the letters on the tailgate of his 49 to update it. There has to be some advantage being this darn old and remembering things like that is one of them.