There's a lot of pros/cons, but ultimately the decision is based
on available time/energy.  The rcs-fast-export script won't
do what is needed without further work.  As a compromise, I've
setup github to provide snapshots of the releases and interim
stable versions.:

https://github.com/ThomasDickey/vile-snapshots
https://github.com/ThomasDickey/pgf-vile-snapshots


(I still have more work to do, to incorporate these into my
workflow, and see a way to improve the older snapshots).

The sources are open (so this is mistitled).

But they're not using git (or svn, etc),
rather rcs.  It would be possible to make something
that exports to git (I see a cvs one for instance,
which appears to lose information - seems that git
has the same mindset as svn...).