I also joked a lot about 'kid hands' 'grown up hands' and 'robot hands' ((Robot hands go added later in response to a Futurama episode, that's what you get when you practice to the point of automatisity)) I would insist that he try with his 'kid hands' and point out that many packages were built with 'GUH' in mind, which is why he had to try, but wasn't succeding.
I wouldn't bring up the 'gifted thing' until you absolutly have to. But you can start introducing the 'Bell Curve' now so he'll be ready - LOL!
Another way to approach is is via the OODA loop. GT kids run through their OODA loops a lot faster. OODA applies also to learning new material.
http://en.wikipedia.org/wiki/OODA_Loop
