Hi, Giangilberto from Milan, so according to the FIA's country guide for Italy foreign disability parking cards that follow the EU standard model are recognised in Italy... Non-EU or non-standard cards may not be fully recognised, you can check this website:
https://disabledmotoring.fia.com/country/italy/
The cameras photograph the license plate, not the dashboard. Therefore, displaying a permit does not prevent the fine; the registered license plate is required.
But listen, I'm on holiday at the moment, and out of sheer curiosity I called the Comune di Assisi to find out what the actual procedure is, and the "Polizia Municipale" told me to send an email to [email protected] with your permit and license plate as soon as possible, even before you leave. They'll assess whether they recognize it and respond. There's a window of up to 72 hours after entering, but use it only as a safety net.
I'll give you two last pieces of advice: whatever the answer, my advice is to stay outside the restricted traffic zone and use taxis, there are very few disabled parking spaces in the historic centers and the streets are like a labyrinth.
Lastly, in Italy, state museums are free for disabled people and their companion.