Here's another from the Legion of Super-Heroes, this time 1983. The character of Ferro Lad was created in 1966, and he was described as a mutant with a "hideously deformed face." He died less than a year later, without ever revealing his face. He showed up in flashbacks and whatnot many times, but his face was never revealed.
He was given an identical twin brother two months after his death, but he only showed up once.
Until 1983, when his face was revealed in this amazing way, but Keith Giffen and Larry Mahlstedt.