Hi Khayden
Judging by the box, it looks like your father's 637 set is from the 1962-63 time period. Hang on to the box, it adds to the history & value of the train.
BTW- I also have a 6059 Red caboose for a 2037 set that I put together. The 2037 is a repaint, but I like it. Take care.