We manufacture this STEEL wrench specifically to remove the brass cylinder insert in the early La Pavoni style machines and variants. Co-fer, La Cara, La Graziella, Olympia Chiasso,and the early flat top base Europiccola machines....other names as well. We use an identical wrench for this job and it has worked fine in every case.
You may need to file the pins depending on the formation/deformation of the holes in YOUR brass cylinder face.