I’m running Audacity 2.1.1 on my OpenSuSE Leap 42.1 x86_64 machine. Audacity was installed from OpenSuSE’s repositories; the RPM file is audacity-2.1.1-96.2.x86_64.rpm.
I have directories for several LP record albums that I generated with Audacity, but the .aup files are missing. For example, I have Side1_data and Side2_data and their subdirectories, but the Side1.aup and Side2.aup files are missing. Is there any way to recreate these, perhaps by copying existing files from another project and editing them with a text editor?
Leslie
Audacity project files are intentionally scrambled and not intended to be used without the AUP project manager. If you’ve been editing or doing production on the show, that’s the end of the story. If your projects are straight, simple recordings, then it’s sometimes possible to recover the work by comparing the time and dates on the files. Stereo shows may still have Left and Right scrambled. Scroll down.
http://manual.audacityteam.org/man/recovery.html
Koz
Thank you for your help. It appears that, since the .aup files were inadvertently deleted outside of Audacity, their projects cannot be recovered.
Live and learn… 
As Koz said, the projects can be recovered if you had not edited the recordings. If you have an ext3 file system, stereo channels may be transposed in places. If you have ext4, transposition should not be a problem.
Gale