Factual error: There is a scene with Gene Kelly dancing at the top of the steps in Montmartre, opposite Sacre Coeur Basilica. In the background you see the lights of the Eiffel Tower. I have seen the view from the top of these steps, and the Eiffel Tower is not visible.
Factual error: The first shot of the calendar shows two days numbered as 20 and March ending on the 24th. In the following shot it's fixed.
Factual error: Actual showboats were very rarely self-propelled. The engine and boilers needed to propel the vessel would have taken up the space needed for the stage, backstage area, and auditorium. As a result, they had to be towed everywhere by a towboat.