Italy's Spoleto - Norcia Railway

Heard of it?
No, neither had I. It's a 950mm narrow gauge line in the mountains, opened as late as 1927 and closed again only 41 years later, in 1968.
I came across it while holidaying in Spoleto, not far from the recent earthquake zone. It is 50km long, full of tunnels, two spirals and many impressive viaducts, including one in an 's' shape.

Today, all the metalwork has gone, but the trackbed and most of the structures survive. Much (all?) of it is useable as a mountain bike path. My wife and I walked the first 8km from Spoleto to the entrance of the summit tunnel, 2km long. It's well worth doing, but bear in mind the gradient, a steady 1 in 50 all of the way to the top (and back down the other side into the next valley). There are some stunning views off the viaducts on the way.

I attach a few photographs, and you can see part 1 of a cab ride video here:

Commentary in Italian, but hardly necessary.

There is a small museum in the Spoleto terminus, but in true Italian style it was closed for the holidays! The loco shed also survives.

I wasn't able to find out a great deal about this line. Does anyone know why it was built so late, and why it closed so soon? What happened to the rolling stock? (I think 5 electric tram locos)