I saw a German film last year called Kill Daddy Goodnight (Das Vaterspiel), 2009. Swiss actress Sabine Timoteo plays a character with alopecia, wears a variety of different wigs throughout the films. At one stage she disrobes for her male companion as they are painting a room. Sabine is genuinely bald-headed and with a bald gash. Amazing when you consider Sabine is normally very hirsute both ends.
I'm sure that those with some time can probably find some photos online.