The classic concepts were part of the 90-vehicle Bertone Group museum collection that was broken up as a result of the Italian design house’s 2008 liquidation.

Lillie Bertone, the widow of the company’s founder, Nuccio Bertone, purchased 84 vehicles for $US2.4 million ($2.3 million). She originally made an offer of 4.56 million euros ($6.24 million) for the entire collection, but was denied as the bankruptcy court refused to settle for less than six million euros ($8.2 million).

British auction house RM Auctions will sell the vehicles in Italy on May 21.

The two vehicles expected to attract the highest bids are the 1967 Lamborghini Marzal and the 1970 Lancia Stratos HF Zero.

The Marzal was driven by Prince Rainier and Princess Grace at the 1967 Monaco Grand Prix and inspired the Espada model, while the legendary Stratos needs no introduction.

Both concepts were penned by Marcello Gandini and both are tipped to sell for up to $2.5 million each.

The 1963 Chevrolet Testudo was designed by Giorgetto Giugiaro and personally driven by Giugiaro to its debut at that year’s Geneva Motor Show. The Testudo is estimated to sell for up to $1.09 million.

Also up for auction are the 1974 Lamborghini Bravo and the 1980 Lamborghini Athon, both of which could reach $300,000, and the 1978 Lancia Sibilo, a potential bargain at a likely $140,000.