I used the discussion (https://sourceforge.net/p/sevenzip/discussion/45797/) announcement and history files for creating the git commits.
https://sourceforge.net/projects/sevenzip/files/7-Zip/(Version)/7z(version)-src.7z/download
https://github.com/7z/ (empty)
https://github.com/kornelski/7z (21.06)
https://github.com/jinfeihan57/p7zip/tree/7zip_21.02
https://github.com/rikyoz/7-Zip (21.07)
https://github.com/zone117x/7zip-mirror (21.03)
https://github.com/mcmilk/7-Zip-zstd (21.03, win)
https://github.com/jinfeihan57/p7zip (17.04, macos & linux)