Very old teen
McDowell was 38 when this came out. Have any older actors played teens?
shareMcDowell was probably 37 when filming took place. He was playing a character who's supposed to be 17-18, which is ridiculous in my opinion. For me this essentially "ruins" the film, although it contains so many other negatives I don't think an age appropriate actor would have made much of a difference.
In the original "Show Boat" (1936) Irene Dunne at 37 plays a character that's 17 for the first half of the movie. She wasn't convincing and again I feel it was a serious flaw.
Aside from these two I can't think of more egregious examples!