Young Woman With Unicorn
Raphael's Portrait of Young Woman with Unicorn (c. 1505-1506) is in the Galleria Borghese, Rome. During a 1934 conservation, overpainting was removed, revealing the unicorn and restoring the original image by eliminating 17th-century additions.
#6 Actually a really cool list
#19 I remember when I first found out that the Roman statues used to be paint to make them appear lifelike. Creepy.