It would seem that a Spinellis-like exercise for SCCS is possible:
PWB1.0 (1978):
I did not find SCCS sources included with the BSD sources on TUHS, but there is a
front-end “sccs” command. For sure, SCCS was used for BSD development. Kirk McKusick’s DVD
has a directory "CSRG/historic1/sccscmds”, but I did not look into this further.
From here the trail probably continues with Solaris, GNU and Bitmover -- all very much
outside my timeframe of research.
Paul
The original Marc Rochchild/John Mashey and team code
from PWB 1.0 can be
found:
http://tuhs.org/Archive/Distributions/USDL/spencer_pwb.tar.gz
In the directory: sys/source/sccs4
The man pages are in the same archive but mixed with the rest of the
commands in usr/man/man*
That said, there is Gnu version of same written C++ if IIRC:
https://www.gnu.org/software/cssc/
And there's more ... but I'll Larry offer details here other than point out
his:
http://www.bitmover.com/bitsccs/ [which is of BitKeeper] is a
more modern implementation still]