Nobel prize nominee?

I have read that too, but I don't think it can be confirmed. The Nobel Prize Committee web site lists all the nominations it received through 1951 on its web site: http://nobelprize.org/nomination/peace/database.html

I could not find any listing related to this cartoon on the database, although it is possible I might have missed the nomination.

So either the nomination came after 1951 (unlikely -- I would think if there was a nomination, it would have come soon after the film's release); or I couldn't find it in the database (possible); or there was no actual Nobel Peace Prize nomination related to the film, and that was something that was just talked about but not made into a formal nomination.