I cheated and looked at the OWH photo gallery published the other day. I'll add another four clues, a fact, and a depressing quote ...
Clue #1: It was not a conference game.
Clue #2: It was not a home game.
Clue #3: It was after WWII (that narrows the window to be between 1945 and 1962).
Clue #4: It was the first meeting ever between the two teams.
Fact: Devaney never coached a game on Black Friday while at Nebraska.
Quote from the 1973 Black Friday at OU (Sooners won 27-0): "Oklahoma invited Nebraska down to play a game of football Friday and only allowed the Cornhuskers to use half the field while the Sooners got to play with the full 100 yards," Tom Ash wrote for The World-Herald. "If six points were awarded for crossing midfield, the score still would have been 27-zip."