> undelete - a tool that would analyse the filesystem and
> report what files and what versions of files it can recover.
Sounds like you are stuck in DOS mode. For an undelete in a real OS, beyond the Windows 'trashcan' desktop GUIs implement, it should be a "Do or Do Not, there is no try." deal. Either have real file versioning, snapshots, etc. or don't bother. Snuffling around on the platters for raw blocks and just blanking out the first letter of file names are bad ideas best left in the dustbin of history.