I have written a small python script that fetches the
linux archive at
git://git.kernel.org/pub/scm/linux/kernel/git/nico/archive.git,
applies patches up to 2.4.0 and commits every patch to git
with a message and a tag.
From there it should be easy to merge old-2.6-bkcvs and
the latest Linux git and have a git archive with the complete
history.

To run it you have to download some patches from
http://gonsolo.de/kernel_history/ and start the script
from the same directory.

It is not perfect, you have to press enter a few times when
patches do not apply. I would be happy to receive feedback
or patches.

After running the script there is a git repository at "kernel" which
is approximately 1GB! After running "git gc" (which takes a long time!)
the pack file is under 100MB, IIRC.

Next step would be to download old-2.6-bkcvs repository from
git.kernel.org and merge/rebase (don't know).

Gonsolo