Hey Sarge,
Even at that res, the threads would still reflect the overhead light. They would be clearly evident in the second pic especially.
GB, it's possible, but very unlikely that they would go through that much effort for a cup that was never a central focus point.
My honest-to-God feeling is that you guys should keep looking. You're close, but not quite there. The real cup is obviously a found object, no sense in settling for close enough when you can get the real deal. Try ebay for older versions of that nissan mug or maybe retailers just have old stock laying around.
-Fred