My model number is not located on the bottom of my MacBook?

First things first, I'm relatively technically savvy and I have googled this and am still on the phone with Apple being switched from operator to operator.

I can't find out whether my MacBook is unibody or not. Someone linked me to a video of Apple's engineer explaining the process of identifying whether it is or not, but it wouldn't load and I can't find it.

Also, whether it was a sticker or print on the bottom of my MacBook that showed the Model Number doesn't matter. It is gone, and I can't find the Model Number online.

Whenever I type my serial number into Apple's website I get this page: http://support.apple.com/kb/SP582