In the mid-1950s, Maserati was immersed in its racing program, and to good effect, since it racked up many podium finishes in Formula One and FIA. But racing stretched its finances. A successful production car would ensure the company’s longevity. Consequently, Maserati abandoned its factory racing program and directed resources to a new Gran Turismo car called the 3500 GT. The mechanical specifications were firmly in place, thanks to Chief Engineer Guilio Alfieri. Altering the racing 350S engine with a wet sump, appending the usual Marelli ignition and Weber carburetors, and adding a selection of British parts such as Girling brakes and a Salisbury rear axle, and voila – Maserati had a GT in the making. However, the car needed bodywork and that is where Pietro Frua comes in. Maserati delivered several chassis to various coachbuilders with a request for prototypes. Frua returned a handful of chassis to Maserati, all coupes but one. Here at RM Sotheby’s London auction, to be sold on November fifth, is that one not-coupe car, a 1958 Maserati 3500 GT Spyder. The sale estimate is £475,000 to £600,000. Whether its appearance in the French movie La Francaise et l’Amour adds any value to the auction or not is hard to say, but this screen capture of the car from the movie definitely adds to the history of the car. We have Araknid78 to thank for this exotic tip!

Powering the 3500 GT is a double-overhead-cam, twelve-valve, straight-six engine. The block and cylinder heads are aluminum, with hemispherical combustion chambers. Displacement is 3485 cc’s, and horsepower output is about 220. The 3500 GT can hustle to 140 mph. This car was restored in 1981 when a replacement 3500 GT engine was fitted, giving purists cause to tear their collective hair out. More fodder for angst: a later owner changed out the four-speed ZF transmission for a five-speed, which the auction house smoothly notes was a “factory” upgrade since the five-speed was original to 3500s starting in 1961. The brakes were also changed to discs; the earliest cars used Girling drums all around.

The interior is near-perfect. Close-ups of the dash show that the gauges are Jaeger, another British contribution. RM Sotheby’s recites ownership history essentially from new, coupled with multiple restorations – some resulting in altered cosmetics. A build sheet provided by the auction house indicates a banana yellow paint job with a turquoise and cream leather interior at some point – perhaps from Frua.

The extravagant body was replete with details like these chrome-garnished intake vents (reminiscent of the 58 Corvette, right?), mild fins carrying the taillights, the broad hood scoop, and a cluster of lights around the grille. In the end, Frua did not win the design contract for the 3500 Gt; instead, Carrozzeria Touring was asked to build the coupe, and Vignale the spyder. Research shows that many coachbuilders supplied one-off 3500s at one point or another – Scaglietti, Moretti, Allemano, Zagato – and some of these occasionally come to market, so if the plain Jane 3500 GT by Vignale is not good enough for you, and you don’t like the changes from original on this Frua, you’ll likely get a crack at a more exotic example someday. In the meantime, any guesses at the final sales price here?