Here's one link which says a bit about
various "rewrites" and the timing involved.

[link|http://www.newadvent.org/cathen/03267a.htm|http://www.newadven...n/03267a.htm]

I have NO idea of the validity. I try not to
get into these types of discussions because the
bottom line is that it almost always involves:
"My passionate ignorance is more powerful than your
indifferent ignorance" arguments. I acknowledge my
ignorance, and my inability to judge. How do I even
know the Torah that I see today is the same as the
original? And WHICH original?

One key thing to remember is history is written by
the winners, and we have no time machines to go
look.

And as Addison pointed out, there is a lot to abhor
no matter who wrote it or when.