I also have:
some Cisco 9000 running NX-OS n9000-dk9 V 6.1(2)I2(1) that gets modelled as a CiscoRT.
They have System Object ID 1.3.6.1.4.1.9.12.3.1.3.1508
And some Cisco MiniUCS running NX-OS ucs-mini-k9-system V 5.0(3)N2(3.11g) that gets modelled as CiscoBG
They have System Object ID 1.3.6.1.4.1.9.12.3.1.3.1454
/Roberth