The Third Man (1949)

It is a little known fact that Charters and Caldicott (or rather Carter and Tombs)  appeared in The Third Man.  Not quite in the film version though; their appearance is restricted to the original script of the film.  The final version of the script, as does the novella that the film is based on, replaces the two characters with a single character, Crabbit.  Reading the original script, the two characters of Carter and Tombs are so obviously Charters and Caldicott; one can imagine the two actors of Basil Radford and Naunton Wayne performing as they did in their many other film appearances.  The actor Wilfred Hyde-White played the part of Crabbit in the film version but it was originally intended for Basil Radford and  Naunton Wayne to play the parts of the two Captains.

The Third Man is a 1949 British film, directed by Carol Reed.  The stars include Joseph Cotten, Alida Valli, Orson Welles, and Trevor Howard.   Considered one of the greatest films of all time, it is celebrated for its atmospheric cinematography, performances, and musical score.

Novelist Graham Greene wrote the screenplay for The Third Man and subsequently published the novella of the same name (it was originally written as preparation for the screenplay). The musical score for the film was written and performed by Anton Karas, using only the zither; probably the only film to ever use the zither instrument in this way.  Audiences found the music such an integral part of the film, that its title music "The Third Man Theme" topped the international music charts in 1950, bringing the then-unknown performer international fame.

Graham Greene's description of the characters, Captain Carter and Captain Tombs, originally to be played by Basil Radford and Naunton Wayne

Captain Carter (to be played by Basil Radford)
Carter has been shifted from regimental duties (for the good of the regiment) to the Cultural Re-education Section of G.H.Q.  He is glad to be out of uniform (it enables him to eat in Austrian restaurants), and the only shadow on the new easy life of organising lectures, etc., at the Cultural Institute is the fear that some mistake may put him back in uniform again.  In spite of this fear he is an ebullient optimistic character.

Captain Tombs (to be played by Naunton Wayne)
With his companion, Carter, Tombs has been shifted to the Cultural Re-education Section of G.H.Q.  Unlike his friend, Tombs is saturine.  He has little hope that the cultural racket will last. Needless to say that neither man has any idea of how the new job should be done, nor indeed of the meaning of culture.