The Allmovie.com review claims that Hitchcock "appears as a mourner during the fake funeral that opens the film." Although I've never seen any other review or article or screenshot that supports this notion.
I even looked at the old women in case he'd dragged up like Albert Finney in Miller's Crossing. Nothing tucked away in the newspaper and no pictures with him in so far.
Marlon, Claudia and Dimby the cats 1989-2005, 2007 and 2010.
Near the end when the characters reach the train station, there is a long shot establishing the area. During this shot I'm sure Hitchcock is shown walking up the platform before cutting to Richard and the General.
"I'd rather be hated for who I am, than loved for who I am not".
Watching this last night and I thought I swear I saw Alfred Hitchcock cameo and strange it not on the IMDb cast list but I did google it and found one: