de_karachi01 can be found here:
http://www.csczfiles.com/file.info?ID=30281
as for the rest,
I have navs for some of those...
They are probably not complete, not place painted, or have severe problems with the bots being able to play on that map.
There's a whole thread on navigation tuning at the forum posted above and you can find my updated, manual nav editing tutorial here:
http://www.csczfiles.com/file.stuff?body=navtutorial