Rattlebattle et al re service schedule distances - the indians cannot 'do' miles so their service distances are always kilometres even if they've written 'miles' in the manual, they can't seem to do the numeric conversion. 500 kilometers is near enough 300 miles and in any case such service intervals are give or take 100 kilometres (or 100 miles

) either way.
I gather, from the service mechanic, that the cam backlash is one of these things that only needs doing if it needs it after checking during oil change with the cover off: some do, some don't. If it ain't bust, fix it until it is sort of thing.
The workshop manual pdf is a bit of a maze with bits in random order, read carefully and try to figure out just what the heck they're on about, there's entire paragraphs inserted in the wrong sections. If instructions are missing, look in preceding or next section, doh. They don't seem to believe in proof-reading, it can be as entertaining as a mystery novel.
I've found similar with japanese engineering, it really, really pains them to do inches, they're incredibly precise but if you ask them do do a metric conversion to fit merikan equipment it will go horribly wrong.