mudgel
Once an audio file is rendered say through an fx, the original file is overwritten and no longer exists, this will include any and all other edits up to a point.
When you save a project using save ss, all those edits are rendered to new audio files.
That's not right, actually. As soon as you bounce, freeze or otherwise render edits/FX, a
new audio file is written
immediately and a new clip is created referencing the new file. Whether or not the original clip goes away depends on whether the audio is bounced to a new track or rendered in place, but the original audio file never gets overwritten in any case.
In this case, it sounds like everything was bounced to new tracks, and then the original clips were deleted, leaving the original audio files 'orphaned'. Orphaned audio files will continue to exist in the project audio folder until deliberately deleted via Windows Explorer, Clean Audio Folder, CWAF Tool or by Save As to a new location.
It seems the OP has a copy of the project with no clean-up having been done, so the orphaned files are still in the audio folder. Unfortunately, the start time and any un-rendered edits are stored with the clip that references the audio file. If the clip is deleted, that info is gone once the project is saved and closed, and cannot be recovered.
The only real solution would be to get a copy of the project that was saved with the original clips still in place.