In moving the history of a project old enough to have used more than one version-control system, I think it's good practice to mark the strata. I'm even interested in pinning down the RCS-to-CVS cutover, if there's enough evidence to establish that.
I've added an issue to the tracker about this: https://gitlab.com/esr/reposurgeon/issues/224 If you have knowledge of the relevant dates or SVN revisions, please leave a comment on the issue. I'm making this a public request becauause there was talk of gluing very old, pre-CVS tarballs to the history. Reposurgeon has primitives to do this gracefully because one of my projects, INTERCAL, was old enough to have pre-CVS tarballs and I felt there was value in preserving that ancient history. I think there is rather more value in preserving GCC's ancient history! If nothing else, there are very few data sets on codebase growth with as long a timespan. Therefore, if you know where I can retrieve pre-CVS tarballs of GCC, please leave the URLs in a comment on that issue thread. I know about the official GCC download page; the oldest tarball on it is evidently from 1997, and I assume that is well after the project was CVSed. I'm looking for older sources. -- <a href="http://www.catb.org/~esr/">Eric S. Raymond</a> The spirit of resistance to government is so valuable on certain occasions, that I wish it always to be kept alive. It will often be exercised when wrong, but better so than not to be exercised at all. I like a little rebellion now and then. -- Thomas Jefferson, letter to Abigail Adams, 1787