Letter from a Young Castro to FDR

As part of my work with the College Board this past weekend, we unexpectedly found a letter from a 12 year old Fidel Castro written to FDR.  One can assume that FRD never saw the letter, but Castro put the White House response on his school's bulletin board.  In it Castro asked for $10 and told him that if FDR needed iron, his birthplace was the perfect place to get it.

Here is an interesting interpretation of the letter that argues that Castro did not need the money since he was going to a private Jesuit school, but posits that perhaps it was part of a class assignment.

Now how could you use this in the class.  My idea is many leaders grew up with normal backgrounds and made a decision to be different at some point.  What might this letter say about Castro and why would a future enemy of the US care, in 1940 about the re-election of one of our presidents?