The unraced F1 projects of 1978 can be found in this article. Just to make it a bit easier with an overview for everyone.
DSC Motorsports
1978 Archieven
Lightning 1976-1979 car-by-car histories
Unraced projects of the 1973 season
Phillip Island Classic to host F1 cars from Europe
Prost AP01B Archieven
Unraced F1, rally and sportscars – 6 of the best
McLaren M24 and McLaren M24B car-by-car histories
1978 Formula One season - Wikipedia
March 2010 Steeplechase Times by ST Publishing - Issuu
A big thank you to all my followers and fans!
Unraced F1, rally and sportscars – 6 of the best
1978 Formula One season - Wikipedia
Frozen in time: the last, unraced car from Graham Hill's Embassy Racing team December 2004 - Motor Sport Magazine
Unraced Projects of the 1997 season