A number of original concept designs for classic car brands such as Jaguar, Austin-Healey, Alvis and Elva are to go on sale in June.
The 34 watercolour and ink drawings are the work of Trevor Fiore, a leading British designer of the 1960s and 70s.
Having lain undiscovered for some time, the designs were found by photographer Michael Cole, whose father had employed Mr Fiore when the artist was producing some of his best work.
Matthew Kershaw, automobile expert for H&H Classic Auctions, described the drawings as "a unique snapshot of what could have been".
"There are striking sports coupes for a whole range of marques, plus convertibles and four-door saloons," Mr Kershaw continued.
"The latter include one entitled Jaguar S-Type but, rather than resembling the manufactured model of that name, it has distinct shades of the Jaguar E-Type and even the sleek NSU RO80 of that period."
Sale of the pieces will take place at the H&H Buxton auction on June 19th.