Look through the records of the most expensive cars ever sold at auction and you'll see Bugattis, Duesenbergs, Aston Martins, Alfa Romeos... but the one model line that pops up again and again is Ferrari's 250 series. Comprising the bulk of Ferrari's models during the 1950s and 60s, the 250 series included such notables as the GTO, Testa Rossa, Lusso and California Spider. But just as vital to Ferrari's dominance of sportcar racing in its heyday was the 250 GT SWB. And RM has got one going up for auction in Arizona next month.

Designed by Pininfarina and cloaked by Scaglietti, the short-wheelbase 250 GT stands as one of the most desirable Ferraris ever made. Chassis 1905 GT was sold to a customer in Italy in 1960 but by 1967 was exported to the United States where it remained in the noted collection of one Norman Blank for 37 years, after which it was displayed at such prestigious concours as Villa d'Este, Pebble Beach, the Quail and Cavallino. Meticulously maintained, it was restored just two years ago. RM isn't saying how much it estimates the car to be worth, but previous examples have sold in the $5 million range.