<< I pointed out before that there was likely a pre-flood Havilah and a
post-flood Havilah. Thus, post-flood descriptions may not have any
resemblence to the pre-flood area. >>
A straight-forward reading of Gen 10:6 suggests that there was no Cush until
after Ham and the Flood; and no Havilah until after Cush. Similarly, Gen
10:22 indicates there was no Asshur until after Shem and the Flood. You can
say they were named after preflood people or places; and that could be; but,
this does not seem to arise from the text of either Gen 2 or 10. It seems
like you are reading your theory into the Bible.
This also raises another question. Since the post-flood Asshur goes back to
5000 BC or so, when are you dating the Flood?