Well, you've also been studying French formally, right? Maybe that has something to do with it.
You should publish it in Malayalam. I don't know what literature in Malayalam looks like but maybe there's a demand?
Well, maybe. There is not that much of a demand for Malayalam literature in general; in bookstores in most towns in Kerala, I'm pretty sure all you could find in Malayalam is evangelical literature because everything else is in English. But of course, there are also lots of Malayalees who can't read English, so at least they are relatively likely to read stuff in their own language. There may be other war memoirs in Malayalam out there, too, but I can't think of any right now at least, so maybe it's worth a shot. I also intend to send the (typed-out version of the) original off to his children since they could read it.
But I've started translating it to English, too. The original was in English anyway, and if I don't do that, none of his other grandchildren will be able to read it. The only other grandchild he has who can even barely read Malayalam is my brother. And I definitely think it would be interesting for the English-language market, too; AFAICT literature related to World War II tends to focus on Europe and especially the Jewish Holocaust, and since this is talking about the experiences of an ordinary Indian villager at the time, I think this would offer an interesting perspective on that.