Turbos : Questions to ask

[Turtle TR]

My brother is looking to by a used turbo. the seller notes:

its brand new. i paid 750 not including shipping from turbonetics. T31 .82 ar exhaust, T04E .60 60 trim intake. ill let it go for $620

http://giftsofaloha.net/eng160/DSCF0022.jpg
It's been installed but never started.

it's a t3/t04 hybrid 4 bolt that we're looking at to complete his list to turbo his GS-R. I'm no turbo expert but what else should I ask regarding this turbo?