Swami...malgudi..tirunelveli..v gangadhar..
searching on the web bout my native brought me to this link
http://www.rediff.com/style/1998/jan/10gang.htm
i think v gangadhar is the guy who was the author of the column"slice of life" in the hindu.the description which he gave when he left tirunelveli seems to match very well with the scene at malgudi when rajam leaves for ever.on top of that rajam's dad was a policeman same goes fr gangadhar..xcept that one doesn't doesn't find an equivalent of swami n mani in the description..
the choice of ambai as my malgudi does seem to gain some credibility.