I made some work on finding out about backupprocedures a few days ago.
One of the things I was doing was to open and go trough the backupfiles that were created by the backup2ws contrib and the standard backup feature via the admin panel. I also looked in to the files produced by the flexbackup.
What I found out were that the flexbackup produced its own file format, while it seems that the backup2ws contrib and the standard admin panel function for backup produced a backupfile that has the same format, and approx the same data content, as far as I can se, compared with that produced by a 911/backup2ws backup.
So what I believe could work would be to use the standard backup function for a restore of a backupfile that is produced by the 911/backup2ws (Of course if it is not more than one backupfile.)
Shoud eventuelly be performed on a test server only, as there is a risk it will not work.
Leave a word if it should be tried and if it should work.