The unraced F1 projects of 1978 can be found in this article. Just to make it a bit easier with an overview for everyone.
Unraced projects of the 1982 season
Formula One (partially found footage of Grand Prix races featuring fatal and/or serious accidents; 1958-1978) - The Lost Media Wiki
Unraced F1, rally and sportscars – 6 of the best
Unraced projects of the 1978 season
1978 Archieven
Unraced projects of the 1979 season
Frozen in time: the last, unraced car from Graham Hill's Embassy Racing team December 2004 - Motor Sport Magazine
Williams, F1 UniONE CAREER by TiroweE Wiki
Ferrari and McLaren's failed IndyCar projects - The Race