what I did to get my HP-7580 All in One to work is, You create the printer you want via the Printer Sharing eBox Module save that. Go back to the Printer Sharing Module/Manage Printers and enable CUPS Stand alone.
First you need to give yourself Admin access to the CUPS Server, here is how.
sudo nano /etc/cups/cupsd.conf What I did was add Allow My IP Address to all the lines that say Allow at the bottom of each line. Like this
# Restrict access to the server...
<Location />
Order allow,deny
Allow localhost
Allow @LOCAL
Allow My IP Address</Location>
# Restrict access to the admin pages...
<Location /admin>
Order allow,deny
Allow localhost
Allow My IP Address</Location>
CTRL+X it will ask you to save Yes and hit enter.
Now here it what made it work for me, I then log into the CUPS Server
https://your ip address:631
That will allow you to Administer the CUPS Printer server. I then use Admin/Find New Printers. Just pick the one you wants and install. Once you have the printer you want go back to eBox In the Users TAB enable all printers you have listed.
Hope this helps it only took me 3 1/2 month to get mine to work.