http://www.turbosquid.com/3d-model/interior/bank-vault

I'd meant to reply to your post but it slipped out of sight and out of mind. I'll PM you if that's ok

Quite apart from any graphical effects of styles, you can often get a more interior-like effect by reversing the sliders in the shadows dialog...slide the Light down and the Dark up. You'll get a more ambient effect, even with shadows still turned on.