I had never heard of CGOS, but this is still up on the Kermit archive! https://kermitproject.org/archive.html Are you Val? Looks like you had to add some hacks to deal with long file naming conventions on CGOS but short filenames on CP/M.
For several of them, it is possibly the only surviving publicly accessible code.
For example, the GUTS (Gothenburg University Timesharing System) implementation-I doubt you will find any other code written for GUTS anywhere online. Maybe some offline archive at some former user still has some code for it, maybe this is all that survives