Latest speculation by modern archeologists is that our friend T-Rex was most likely a scavenger rather than a predator. Note the diminuative forelimbs: not much good for grabbing and holding prey. Nor are the claws on the feet adapted for ripping flesh as those of a velociraptor are. That being said, the red head may be appropriate for this guy - the same as a turkey vulture.
Really nice modelling that you are doing, Mark!