definitely worth a resto imho, especially if you can do any welding etc yourself. as said try to get away with scrap value.
imagine there isn't much of a landy parts scene in Italy so getting big items shipped over could be a pita unless you travel between here and there a lot
my s3 has fender seats, much comfier, I am not bothered about originality, I just want a truck that goes :D
one of the beauties of landies you can do what you want with them, be boring if they were all as they left the factory
a lot of garages - mine included - seem to have been designed so you can get a car in - if it isn't full of junk - but barely be able to open the doors to squeeze out
plenty of good resto threads in here - some good ones at the top op the page - and in the members vehicles sections, this is another good one https://www.landyzone.co.uk/land-rover/johnnys-series-3-resto-project.178801/
you can see exactly what some people have done
I would go for inside air, there are probably enough body gaps that condensation on the windows shouldn't be an issue like it is on modern cars if you leave the heater on re-circulate.