If it's a boot or a conversion, it's incredibly well done.
The only way to find out is by cracking open that cart. Start from the bottom, applying pressure to the side that gives, you'll see when you put presure on one side and the other which side has the tabs (it's been awhile so I forget which side). You'll separate the bottom slightly, just try tokeep it pulled open by putting soemthing like folded paper in between the two halves and then push on the side to release those tabs, then the cart should come open. Just don't open it too far so the label will stay intact and won't get creased.
Then upload us some pics of the boards!
(if anyone can explain this better feel free to do so, it's been years since I've opened a cart)