Vagnozzi seems to be a one timer. Do you know Grazia Fei, maybe the widow Dona Inez?
From pics this should be Gianni Pulone on the left? has his identity been confirmed?
IMDB has Don Carlos as Andrea Fantasia, I’m not sure. Here with Sergio Sagnotti and Dino Strano
I did not spot Artemio Antonini but in minor roles: Marcello Meconizzi, Alba Maiolini, Romano Milani, Maurizio Streccioni, Romano Targa, Mario Dionisi, Luciano Bonanni, Attilio Severini, Franco Moruzzi, Gilberto Galimberti, Rocco Lerro, Luigi Mannoia (tbc)