Vanessa Redgrave and Angela Lansbury were first considered for the roles of Lady Hester and Mary, but due their schedule problems they were replaced by Maggie Smith and Joan Plowright.
The breaking news radio announcement reporting the Japanese attack on Pearl Harbor also included information about President Roosevelt's speech the next day and the subsequent US declaration of war against Germany, Japan, and Italy. In effect it was a summary of two days' events and wouldn't be a breaking news announcement.
The ladies protect the frescoes by building a wall around them using sandbags. But the bags are obviously filled with something light and fluffy, such as kapok or cotton.
Lady Hester: Do look. Oh, look! Look at that ridiculous American monstrosity they've given the child. What do they call them? Knickerbocker glories. Oh! It's amazing. They can even vulgarize ice cream.