You can be sure 100% now, it's real
EDIT: However, a new replica is coming out from G&P, and it's the replica of the scope you saw up above on my M4, that is, an Acog TA31F exact copy:
http://www.gp-web.com/en/productspop.php?pid=832
As you can see, it is incredibly well made.
Naturally the fiberoptics on the replica won't work (i.e., you won't have the lit red arrow inside) and the red tube on it is just a dummy but still, I find it hard to tell between the real one and this new replica.