Here's what mine looks like, but keep in mind that mine's a re-badge. It has an Allen-Bradley logo, and it says 'Industrial Computer, Manufactured by IBM Corporation' on the front badge. It's Model number is 5531. The drives are stashed behind a trapdoor on the front. There is a foam filter and an extra fan behind the louvers to the left. It is distingushed by having a dark grey case ('Industrial Grey'), rather than the usual beige.
--T