Good post.
My primary education was done in a small school by the side of this narrow gauge line. We used to run to see these trains. Sorry to see them decay. I would have seen most of them as there were only very few trains in this line and they mostly operated on office hours.
There is a big issue in this line as there are most number of level crossings on this line and lot of people have already lost their lives due to poor visibility of the train and engine drivers not tooting horn as required , when they arrive a level crossing. If a fast train is introduced there will not be possibility of this as some of these level crossings are very close by.
If this line is to be improved lot of planning is needed. Lot of acquisition is needed and all squatters needed to be relocated. These people have lived in these for over one generation and cannot be evicted using only military or police power. Adequate safety measures should be taken for adjoining schools, hospitals, level crossings etc.
If not it would be another tragedy like the garbage mountain!