LOL you mean RTFM
Yes I have been reading it, and the actual answer to my question was about views.
Linux is natively discovered by NPM, however there are two issues
1: The information displayed need to be set up in "views by vendor"
2: The vendor matching is a bit shite and especially for net-snmp based nodes, can be very variable resulting in linux boxes ending up in different groups based on their dist, while a range of other linux based appliances (firewalls, proxies, linux based network appliances etc) all ending up in the net-snmp bucket even though they are in fact quite different beasts.
I have another thumb out at the moment asking about how to manually do the vendor groupings to sanitise the vendor listings but my hope is small.