Oh great! So do you think that playing with the Setpatch parameter I can have the luck to make the CV643D to be seen by the FF40?
Well, you definitely need a working CPU library. In your Sys:Libs drawer, there should be a file named 68040.library, which is loaded by setpatch if a 68040 processor is detected. However, this Commodore supplied library doesn't work with every accelerator - some require their own special library.
I suspect this to be the problem with the Fusion Forty (in which case the library from the MMULib package might not work, either).
My advice - download the Fusion Forty software
here, see if it includes a 68040.library. Install it, uncomment setpatch and give it a try.