Does anybody know anything about chassis numbers of these cars? DSJ, in The Racing Car Review tells us that the works drivers kept the same car for most of the championship races: Ascari ( number 5), Farina (4), Villoresi (3, 6 at Spa), Hawthorn (1). Number 2 was used as a spare early in the season, number 6 later. David McKinney's notes say that all six cars, with the exception of number 5, were updated with 625 engines for 1954. One new car was built for 1954 (7), another for 1955 (8).
That seems clear enough but what about the 1953 2.5-litre cars? The Racing Car Review says that Farina's car at Rouen was stamped 3 and Hawthorn's 4 and that Hawthorn's Silverstone Libre car was also 4. Were these new cars, otherwise unaccounted for, or was Ferrari juggling identities?