Is my iPhone 4 original?

So I recently bought a used iPhone 4 (White) running on iOS 7.1.2 and went to check if its original, It listed a valid imei and serial number and is even registered on apple.com and is connected to App Store, doesn't have a dull screen, has high quality camera, keeps up with fast scrolls and is free of pixels.

but when I ejected my sim tray, it listed a different imei and serial number for some reason, so I checked the different imei and serial and still came out as valid although it was a bit suspicious. just wanna know if its original, and if it isn't then I'll just store it in my drawer as a novelty item.