How to extract changes from unrevisioned repository

[Kyle Altendorf]

There is one person at work that I have been unable to convince to use
Mercurial.  Not only is he not using revision control but the .hg
folder has been deleted from his copies of the project.  I am trying
to bring whatever changes were made in that uncontrolled copy back
into the main repo.  The issue I am having is that as I try to find
the 'parent' I am finding that certain changes have been cherry picked
out of various changesets in the controlled project while ignoring
other changes in the same or intermediate changesets.  The result is
that I am having difficulty picking a single parent from which to try
to merge the uncontrolled copy back in.

Is there some method for resolving this issue other than double
checking every difference?  I could imagine a tool that would reverse
every hunk in the repository and try to apply it to the uncontrolled
copy to identify which changes had been applied but I assume that
there would be numerous problems with that.  Any comments would be
appreciated.

Thanks,
-kyle