On my Appia I had the headline replaced by a trimmer. The front and rear screens need to be removed.
On the B20 I removed the headlining and took it to a trimmer the headlining of both cars is sewn onto to rods
which are sprung into the roof. On the B20 I fitted headlining with the help of a friend.
The other problem is all the others bits of trim next to the headlining will have faded.
I have heard that Elvezio will make Lancia headlinings see
https://www.elvezio.com/en/lancia/lancia-appia-2nd-3rd-series.htmlOtherwise a local trimmer will be able to make the headlining using you old one as a pattern and all the other bits of trim.