Xpost from Facepunch:

http://i.imgur.com/6iDOf65.png

I discovered you can put the item importer preview stuff in the loadout preview which lends itself to interesting possibilities. Basically, it's a miniature in-game HLMV with the same controls. You can pan the camera, zoom, and rotate up/down instead of just left/right. Plus you can even change the light position. When you change items/presets it resets back to the default position/rotation.

Edit a file in resource\ui called classloadoutpanel.res with a text editor. From there, find a string that says something along the lines of "allow_rot" under "classmodelpanel". Change "allow_rot" to "allow_manip", and now this feature can be in your own hud. (The team switcher buttons are separate from this)

Controls for whoever has not used HLMV:

To change the lighting position, hold CTRL and drag with your Left Mouse Button.
To pan the camera, hold SHIFT and drag with your Left Mouse Button.
To zoom, drag up/down with your Right Mouse Button.
To rotate the camera, drag with your Left Mouse Button, either left/right or up/down.