(source)
The "ugly aircraft" from your video is a Vought F6U Pirate, the aircraft furthest from the camera: you saw it flying in formation with Chance Vought Cutlass F7U-1, no. 124419, the fifth production aircraft. Note the deep fin extensions on the underside and the long nose instrumentation boom.
The picture below was taken by aviation photographer William J Balogh, with the nose painted white with a red arrow, possibly at the Detroit National Air Races in 1951.
(source)
During a test flight in February 21 1951 (source incorrectly says it's a F7U-3)
The white nose design seems to have been removed at some point when the aircraft was assigned to the Flight Test Division at NAS Patuxent River (below)
This plane, piloted by John Starr Hill, crashed on landing on 23 October 1953 at Patuxent River and was written off. (note - the record says 1 fatality, but the pilot was not killed.)
(Despite the same Modex number (and what the caption says) this is not the same aircraft depicted here at Ft Lauderdale in a rather sorry state in 1978, which is a F7U-3 / 129582.)