There's an entire website devoted to this, and not just aviation. Can't remember the name of it, but people spend hours watching films in order to notice the 50-odd "howlers" in each and every one, like the fact that the star's dinner fork had food residue on it in one take and not in the next one. Or than two jacket buttons were buttoned in one scene and only one in the next scene. Truly obsessional.
Yet even they wouldn't notice a 1950s registration on a 1930s airplane...