The two Don Pardo audio clips and the first four minutes of audio-only NBC coverage after the Pardo clips come courtesy of Phil Gries, the developer and owner of Archival Television Audio, Inc.
Gries taped that material directly over the air as it was being broadcast live by the NBC Television Network on 11/22/63, and Phil's tape recorded version of those initial few minutes of NBC's November 22nd coverage is the only source for that material known to exist.
The excellent video quality of my two-part NBC series comes from the collection of a friend of mine at Facebook who prefers to remain anonymous. He was kind enough to provide me with a digital copy of this NBC material in early November 2015.
Here's a message I sent to the anonymous source on November 6, 2015:
"You're going to have to come here to my house to help me pick my jaw up off the floor, because I simply cannot BELIEVE the incredibly good video quality of this NBC footage you just sent me. It's absolutely amazing. I have never seen it look this clear! Thank you so much (again) for providing me with this sterling version of the NBC coverage." -- David Von Pein
RAW NBC-TV FILES:
INTERVIEW WITH DON PARDO
(MAY 14, 1998):
75 SCREEN CAPTURES FROM
THE NBC-TV COVERAGE:
16 SAMPLE IMAGES:
MORE TELEVISION AND RADIO COVERAGE
FROM NOVEMBER 22-25, 1963: