there is an ready Indigo
model (for texturing) in inventor format if u install Open Inventor demos u can find it in /usr/share/ folder. those demos are used by open inventor and showcase as well. as i recall i exported the *.iv to *.rib then opened it in maya, but i not have at the moment any working maya install so here the *.iv files ...
what amazed me was the quite detailed robocop model
i found there, here it is although out of topic
let somebody says now that SGI`s are not about having fun
the Octane can be found on octane demos cd 1.1 or 1.3, also in open inventor format ? or i think was vrml ? can`t remember now but i will dive for it another day
also the "chrome skins" O2 in open inventor format can be found on Ian`s site in the benchmark part / or on O2 out of box CD and O2 demos CD ....