Thought of you when this turned up on a former abm-l-ites facebook feed.

http://newsfeed.time.com/2011/04/15/whos-that-lady-new-stamp-features-wrong-statue-of-liberty/

Heehee.

This sort of thing happens a lot with stamp design, especially now when a lot of the designing is done by advertising agencies. But even back in the past there's been a lot of design mistakes made, some of which don't get picked up until long after the stamps concerned have been withdrawn from sale. Another popular design mistake is "wrong portrait" - a stamp issued to honour some Historic Person turns out to show a painting of his son, or his brother, or someong completely different painted by the same artist.