A fellow member (QuantumCat76) of the Dutch coffee forum www.koffiepraat.nl mentioned that he had found a cheap tool to fasten the boiler of his La Pavoni to the base. He could swivel the boiler left/right when pulling the lever sideways.
He explained that an 80--135mm oil filter wrench does the job and I bought one as well. Below I post some pictures, also indicating how it would fit on the base. I did not take off the pressostat pipe so the tool does not actually fit in the photo but the base of this Pavoni is fine so I did not want to take it apart.
