Ferrari in 2018 launched the new Icona series aimed at collectors looking to purchase a one-off or low-volume Ferrari with styling unashamedly cribbed from past classics.

The first in the series were the 812-based Monza SP1 and Monza SP2 cars, inspired by early racing barchettas like the original 750 Monza and 860 Monza of the 1950s.

The next member in the series, code-named F251, is expected to be revealed in November, and according to forum chatter the inspiration for the car is the 330 P4 from 1967. Backing up the rumors is the recent sighting of a heavily camouflaged prototype testing near Ferrari's Maranello headquarters.

Photos of the prototype, posted to Twitter by user El Bar de Jenson, feature design traits shared with some versions of the 330 P4, like the fender mounted side mirrors, curvaceous body, and wide, wedge-like tail.

It's possible that the F251 is the mystery car we spotted in March, which used a makeshift LaFerrari body to hide its mechanicals. Some of the details of that earlier tester, like the wheels and high-mounted exhaust tips, match up with the prototype shown above.

Glickenhaus Ferrari P4/5

Glickenhaus Ferrari P4/5

With any luck, the resulting design for the F251 will be something like the revived De Tomaso's utterly gorgeous P72. Don't be surprised if there are also some similarities with James Glickenhaus' Ferrari P4/5 by Pininfarina, whose design was also inspired by the 330 P4.

The original 330 P4, of which just three examples were built plus a fourth based on the chassis of the previous P3, was a sports prototype built for endurance racing. The most famous victory was at the 1967 24 Hours of Daytona, where a 330 P4 came in first, second and third.