TL;DR:
Try this in The Ultimate Doom v1.9 (original DOS, this specific version only) https://github.com/kgsws/doom_ace/tree/master/savegame
Or try this in Doom 2 v1.9 (original DOS, this specific version only)
https://github.com/kgsws/doom_ace/tree/doom2/savegame
And now full version.
About a week ago i was thinking that it could be interesting to have original DOS doom mods that would allow more advanced changes, like dehacked. But without modifying the EXE.
After to