Hope you have read Part 1.
One stretch of railway which received much attention from KA was the then metre-gauge section between Nandyal and Giddalur. We start with the map provided in the story “The Killer from Hyderabad”.
Going west to east one starts from Nandyal. The area of interest starts from Gazulapalli station. From there the line turns north-east to Basavapuram station, makes an U- turn to Chelama station and then eastwards to Bogara station, which seems to be near the highway.
After a sharper U-turn you reach Diguvametta and continuing east you reach Giddalur. There is another story centred around Diguvametta.
Here is a survey map of around the same time:
You may have to strain your eyes a bit, but you should be able to make out that all the stations (except Bogara) are marked.
But the line was converted to broad gauge in the mid-1990s and the section was realigned to give a straighter route. It has also been electrified.
Here is a basic map showing the old and new alignments:
This is from “The Great Indian Railway Atlas”, 2015 edition. While this is the best map of the Indian Railways available to the public, it has one flaw in that it does not show the OLD location of Chelama station but only the NEW station. One would expect the station to be named New Chelama, which is the practice followed in the railways elsewhere in India. The old station, as you can guess, lies between Basavapuram and Bogara as shown in the old map.
Also, I have seen timetables of various periods from the 1930s onward. The stations of Basavapuram and Bogara do not appear anywhere. Perhaps they functioned only for a short period. Or perhaps they were “non-commercial” stations which existed only for operational purposes (e.g. crossing) but had no passenger services.
In the 3rd and 4th parts, I will add some more information and videos about the points of interest along the new line. Of special interest are the remains of the Dorabavi Viaduct which was between Bogara and Diguvametta and about 1 km long
Numerous pictures and Youtube videos can be seen on the net covering these places. Also try “Nallamalla Hills” and “Dorabavi” as keywords. Most of the videos have commentary in Telugu, though some have English subtitles.