no notam?
Micheloni,
You say ther are no notams advising of downgraded equipment, but if a cat III airport is only allowing cat II approaches, surely that would be published in a Notam.... They might not specify why the downgrade is in place. But you will find that one piece of equipment/lighting is not at the required standard for cat III ops. They wont restict operations just to be difficult!
If you land below cat II minima, you will be just as wrong as doing as if it is a cat I airport. For Cat III ops, you, the aircraft, and the airport must comply with cat III qualifications.