There is some confusion with regard to the actor Giovanni Petrucci. It seems he is confused with the much older Giovanni Petti, who sometimes used the name Petrucci.
Petrucci has his own category page on the SWDB, see Category:Giovanni Petrucci - The Spaghetti Western Database Here he is credited with twelve films. But actually he might only have been in four, possibly five of them. They are: Da uomo a uomo (a Mexican, Pedro’s henceman), El Desperado (younger captive solider), Quanto costa morire (young townsman killed trying to escape), Sono Sartana, il vostro becchino (deputy), and possibly Il Bianco, il giallo, il nero (I wouldn’t know, I haven’t seen it and have no wish to). The rest of the films mentioned here I think are films with Petti.
From Wikipedia we can learn that Giovanni Petrucci was born in Rome on the 5th of April 1941, son of the director Tonio Petrucci, played his first part in a film in Cortile 15 years old, and went on to play in Michelangelo Antonioni’s L’avventura. He was also into theatre and played in Ionesco’s La Cantatrice Chauve and En attendant Godot by Beckett. After his film career ended 1980, he dedicated himself to dubbing.
I think this might be the most accurate filmography to be found on him: Giovanni Petrucci filmografia | MYmovies.it
Petrucci in Quanta costa mourir: ImageBam