It was one of Ferrari’s two open-topped versions of their Tour de France Berlinetta, the other having been the California Spyder. Covered in Part 2, the first four vehicles in the series were essentially prototypes, all featuring unique body and interior detailing although the chassis and mechanical components were much the same as the subsequent 36 production units featured here. Incorporating the same Tipo 508 B tubular steel ladder type chassis as the Tour de France Berlinetta's then (later evolving into C and D specifications), this frame was a traditional Ferrari affair. Independent coil sprung front suspension was combined with a live rear axle and hydraulic drum brakes although one very well-known exception was the prototype chassis 0655 GT. Ferrari Grand Prix ace Peter Collins had Dunlop disc brakes and alloy wheels fitted to this, his personal vehicle, the latter in replacement of 72-spoke Borrani wire wheels fitted normally. Designated Tipo 128 B, the Colombo-derived 60° V12 featured the familiar 2953cc displacement thanks to a bore and stroke of 73mm x 58.8mm respectively.

Output varied between 220 and 240bhp at 7000rpm, the exact figure being influenced by customers requests for any competition-derived options like high-lift camshafts and cylinder heads, Abarth sports exhausts or velocity stacks, for example. Compression was also regularly varied between 8.5:1 and 9.5:1 whilst most Series I Cabriolet's were fitted with three twin choke Weber 36 DCL 3 downdraught carburettors. Of wet-sump lubrication and with a four-speed full synchromesh overdrive gearbox, it's worth noting that early examples were fitted with an unreliable single distributor set up, Ferrari approving the retro-fitting of a twin distributor after just a few examples had left the works. Performance of the Series I Cabriolet was outstanding, not far off the Tour de France Berlinetta and more or less on a par with the California Spyder. A maximum speed of 135mph and 0-60 in 7.1 seconds were possible. Meanwhile, Pinin Farina had established a strong relationship with Ferrari, most bodywork from the Maranello back catalogue either having been designed or constructed by the Turin carrozzeria.

An elegant chrome-lipped engine scoop fed cool air to the motor, the rear wings incorporating a kick-up just behind the doors. Like at the front, the rear wings were also creased, these sloping gently to the elegant tail beneath which four chrome-tipped exhaust outlet pipes lay. The interior of the Series I Cabriolet's struck a perfect balance between luxury and performance, cabin appointments providing clients with a very comfortable experience, fine leather and carpeting mixing perfectly with Competizione components of the day. A wood-rimmed and triple aluminium spoked Nardi steering wheel would normally be combined with a crackle black dash, a flip-up Pinin Farina ashtray and heavily cowled instrumentation all having been executed in the finest period style. Launched at the Geneva Salon during March 1957, the 250 GT proved an immediate hit with wealthy clients who had long been requiring an open-topped GT car of real performance and just a little luxury. Finding owners with several notable figures of late fifties high society, the 250 GT Pinin Farina Cabriolet made further public appearances at Frankfurt then Paris and later Turin during 1957.

As was normal Ferrari practice, a number of developments were implemented during the 250 GT Cabriolet's production run, the most notable of these having been the chassis and engine upgrades. For example, the Tipo 508/128 B chassis and engines were switched to 508/128 C components and these subsequently substituted for 508/128 D units by the end of production. Two examples were finished in right-hand drive configuration (chassis’ 0709 GT and 0921 GT) whilst bumpers were changed from the stylised twin units seen on early Series I to a more conventional full-width design towards the end. Furthermore, whilst some examples featured fender vents and the like, a handful of very late Series I's were completed to a rarely seen open headlight configuration, much like the similar treatment used on some California Spyder's. Chassis numbers of the 36 Series I Cabriolet are listed below but although the model was the first attempt at a standardised Cabriolet, Ferrari would not make any significant strides towards a real production model until the Series II of 1959.

250 GT PF Cabriolet Series I Chassis Index