Thanks Rob, I will add them manually then. However I have found that using the "Router/Switch" device type seems to have worked better as it has discovered the LLDP neighbours and connected devces, where the "universal device" only knows it's up.
Oddly neither can detect the interfaces which are probably the most widely recognised standard MIBs. I would have thought it more likely to get these right than the LLDP MIB but it repeatedly logs the error "Error in SNMP polling: Unknown error(interface_monitor)".
It also doesn't seem to be able to get the unit mac address and sysname/location (again really basic standard RFC MIBs) which means it won't link it to the neighbour details on other devices and therefore can't tell that they are inter-connected whichis a shame as it is the upstream router for the HP switches it does understand.
It seems an odd mix of things that work and things which don't