Roberto Clemente sits down with WPXI [then-WIIC]'s Sam Nover in October 1972, less than 3 months before his untimely passing. This is definitely his final at-length interview, and probably his only surviving extended interview that was captured visually. This was re-run by WPXI for the first time in 1989, and again on New Year's Eve 1997 [marking the 25th anniversary of his death], which is the source of this upload. I'm not sure if it's been shown again since then. In its original rerun, Sam Nover apologizes for the video quality, and John Fedko does the same in 1997, so I feel no obligation to do so in 2018!
UPDATE: It was announced today [12-4-18] that Sam Nover, who conducted this interview with Roberto, has died at the age of 77. RIP to a Pittsburgh broadcasting legend.