Finally I managed to hear from the dealer ...
the piece (complete with electronics) is available in a couple of days at a cost of € 110.00 (with VAT and assembly)

I thought it was worse

 

That's very reasonable.

You can reach the 2 bolts from under the headliner. Simon from Powerfuluk did a video.
Set your Incontrol in service mode, because you disconnect for a short time the connection.
I got prompt a call.. that's why I know.

 

Grazie ! ... Thank you

 

basel I’m glad to see your smiles, didn’t want to be taken as disrespectful, just my attempt at humor. Glad to see that the replacement part is not too expensive. I would have expected it to be much more. Good luck with your repair. I don’t normally keep my Defender in the garage, but had to swap cars out today and was holding my breath as I backed the Defender in, getting out every 6 inches to assess the clearance. Turns out I had inches to spare, otherwise I would be searching for the same part as you. In Southern Florida, but can’t wait to revisit Italy. Ciao!

 

don't worry Chuk ... I love the humor ... which then translated into Italian is even more likeable
I keep Defender in the garage because it often hails here in the Po Valley ... ( exactly here ) ...
in that garage where I touched the fin I have already parked it dozens of times ... always in reverse ... this time I accelerated too much and the car lifted, she soared !!!
I've never been to the usa...but one day I'm sure I'll come

 

How did you get your hands in there to disconnect and remove the bolts? I removed the top piece and disconnected the liner but didn't have anywhere near the space to disconnect the antennas or remove the bolts.

 

It is not so hard with the the right socket, only 2 10mm nuts. Lift the antenna and unplug /plug the connectors from the outside.

 

Ok, so the metal plate drops when you press the black clip? I also couldn't get the clip depressed but might need tiny pliers