Two questions about the 1921 Targa Florio.
1-All the reports show one Rodolfo (or Antonio?) Caruso participating in the 1921 edition of the Targa Florio at the wheel of the #31 car (DNF).
The car is indicated to be a Imera, Himera, Impera or Immera, depending on the source.
The site TargaFlorio.info has a picture of the #31 competitor:
Looking to the shape of the front radiator, and comparing with other contemporary pictures, the car seems to me definitely an Impéria, the Belgian automobile produced in Liège.
2-Rodolfo Caruso was the elder son of the great opera singer Enrico Caruso. He was a talented "gentleman-driver" who competed with relative success in the 1920s. He ran a Chrysler dealership in Florence and in 1928 shared a Chrysler 72 with Emilio Materassi in the Mille Miglia. Later that same year he finished second overall in the Circuito di Caserta. Born in 1898, he was 23 years old in 1921 and it is conceivable he participated in the 1921 Targa Florio, which anyhow could have been his very racing debut.