Here’s a pedantic point. In the original novel that inspired this puzzle, the first name of one of the thematic characters is never given. The name hinted at by the extra word in 12A is used once in the book to refer to a character who is part of the “back story” and does not appear. Oddly, this character had been called “Toby” in an earlier place in the book, and had the same military rank as the thematic character.
I think that the name in question was used in the 1974 movie for this thematic character, but all the other names in the puzzle are as in the book - in the movie, at least one other thematic character was given two different first names from those used in the book, and some other characters had different surnames. As I understand it, the 2017 remake takes even more liberties with names, ranks and titles.