I now have a machine with everything on it working as I want it to, albeit
my wife's. When I handed it over to her, she was over the moon with it but
within seconds there was a 'I don't know what I I did but the icons have
gone'. She was referring to the desktop icons I had created on the visible
desktop folder.

I couldn't get them back and in the process made things worse. A horizontal
white band appeared occupying most of the screen with just the kicker and a
similarly sized band at the top. In the end I had to delete her a a use and
recreate her as a new user.

While I was recreating the desktop icons I remembered what a chore it is to
rename each one so a to remove the suffix .desktop from each name. What
thinking led to it being there in the first place!

Anyway, might there be a way of locking the folder/icons in place to prevent
accidental deletion?