sorry for the delay; i got pulled off this one for a few days.
Jane, your suggestion worked: I have now got the import working straight from your new EGG file (unzipped)..
Now I see a new device class.. 
So I imported all my printers in here instead; setup the SNMP community settings...
I see the additional item 'TwoNMS.snmp.PrinterMap' inside the /Printer/PrinterMIB/Device/Modeller Plugins
Like so: http://community.zenoss.org/servlet/JiveServlet/showImage/102-11311-3-8889/modelersmall.png
Unfortunately I don't see 'Components' like in this picture: http://community.zenoss.org/servlet/JiveServlet/showImage/102-11311-3-8890/componentgraphsmall.png
I had a look to see if the reports worked... unfortunately they didn't load any data..
unsure what to do i'm restarting the monitoring host (see if the service restart will kick the discovery again).. if that works great.. failing that, leaving it over night to collect some data.. might also do the trick.
Any other suggestions - please just shout!