As terrible as SCCS is, is there any chance to have a CSSC package?
(CSSC is a GNU program so it would make sense.)
No. But you should be able to offer one under your own project.
Well, it's not for my project. It's just that I've had to use it a few times to convert some older SCCS projects to something decent. I suspect others have been in my position. Two things worth mentioning:
1. There is a package for Bazaar.
2. SCCS is defined by POSIX.
That said, I am willing to prepare the package myself if that's what the problem is.