The Third Man -- casting

The casting of the film The Third Man seems to have been a fairly chaotic process.  In his book In Search of the Third Man, Charles Drazin devotes several pages to describing how everybody and his brother was considered for one or other of the main parts at one stage or another.
 
The three male leads in the film are Harry Lime, eventually played by Orson Welles, his friend Holly Martins (Joseph Cotten), and Major Calloway (Trevor Howard).  Among the actors who were suggested for these parts were Cary Grant, James Stewart, Robert Taylor, Robert Mitchum, Rex Harrison, Ralph Richardson, and even (apparently) Noel Coward.  In the end, the casting was a compromise.  The director (Carol Reed) didn't want Cotten, and the producer (David O. Selznick) did not want Welles.
 
Orson Welles is certainly the most famous name of any of them today, but in 1948, when casting took place, Welles was regarded as box-office poison.  He himself was not particularly interested in the part, seeing it merely as a payday which would enable him to go off and pursue other projects.  He signed the contract readily enough (he would sign anything) but then disappeared.  When eventually found, in Rome, he took some persuading to go to Vienna.
 
Even when he arrived, he was not particularly co-operative.  His part was essentially a small one, and quite a lot of the scenes in which he appeared were set in Vienna's sewers.  Welles took one look at these, and inhaled one breath of the atmosphere, and declared that he wasn't going anywhere near them.  So any sewer scenes which included Welles had to be shot back at Shepperton Studios, in England.
 
Today, of course, we know that Welles dominates the picture.  No one remembers much about The Third Man except that Orson Welles starred in it.  But that was not the way it appeared to the participants at the time.
 
About twenty-five years ago, I wrote a couple of scripts for the American producer and director Sheldon Reynolds.  Sheldon told me that, originally, Trevor Howard was offered the part of Harry Lime.  Howard, however, read the script, and found that Harry Lime appeared on only eleven pages of it.  Major Calloway, on the other hand, had a great deal of screen time.  So Howard said thanks very much, he would pass on the Harry Lime part but he would gladly play the English Major.
 
Drazin doesn't tell us this story, so he either doesn't know about it or doesn't believe it.  And indeed it does sound a bit questionable to me.  Given the general chaos which surrounded casting, it may be true.  But it sounds to me like one those amusing and self-deprecating stories which may have gradually developed in the mind of Trevor Howard to entertain his drinking buddies.  And Howard, of course, was a strong contender for the much-contested title of the world's most frequently pissed actor.  Cotten was also a heavy drinker, and Welles only agreed to turn up for shooting after one of the director's minions got him thoroughly drunk.
 
Finally, lest anyone accuses us of sexism, we must record that Selznick at least saw the film as a vehicle for Alida Valli.  Now a forgotten name, she was at that time something of a hot property.  And indeed she played her part so well that one almost takes her for granted.