To revert a TF 3.01 patched install to "vanila" run STEAM file check, this re-write modded files for default ones (and probable create a new
...:\Documents\1C SoftClub\il-2 sturmovik cliffs of dover folder).
After copy the folder "IL-2 Sturmovik Cliffs of Dover" from
...:\Steam\steamapps\common\IL-2 Sturmovik Cliffs of Dover
to (example) D:\Cliffs of Dover
Rename for (suggestion) "Cliffs of Dover - Malta" and install the Malta MOD - see Reade-me instruction to make a specific shortcut for this version.
Do the same to re-install TF 3.0/3.01 patch - TF 4.0 Patch is scheduled to be released tomorrow (previous versions is need until come a unified install).
You can have many copy's of CLoD™ as you need (or you HDD allow

).
Sokol1