Does anyone remember a very short scene when they are going past a group of street musicians, the violin player of which bears a remarkable resemblance to Jack Benny?
The credits here at IMDb do not include Benny's name. Could it have possibly been him in a cameo?
From viewing on a TV screen, someone might mistake the violinist for the comedian in that brief glimpse. But as this Mankiewicz fan has seen this picture multiple times on film, projected onto a considerably larger screen, I can confirm for you that it is NOT Jack Benny.
Most great films deserve a more appreciative audience than they get.