Cinnamon DE

[Grizzly]

Hi All

I trying to assist a friend with adding (for now) cinnamon DE to his Noble 
default Gnome install

I checked the repos (and had him do the same)

sudo apt update
sudo apt-cache policy cinnamon-desktop-enviroment

we both got exactly the same positive output, so then

sudo apt install cinnamon-desktop-enviroment

now the results were different, here I got the usual checks then a (very long) 
list of files that "would / should / could" be installed (I choose not to go 
further)

but my friend only got as far as the checks then

E: cinnamon-desktop=enviroment package not found (or similar wording)

confused I had him the copy paste the "cinnamon-desktop-enviroment" part from 
the first command (to rule out a typo) after "sudo apt install", but that made 
no difference

we then went through our other settings (which server we were using etc) all 
were the same here and there

I'm out of ideas, the only difference is I'm using Ubuntu-Unity where he has 
(as above) the "default" Gnome? install

any ideas please